ChE Reviewer

7/27/2019 ChE Reviewer

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NO QUESTION A B

1 A valve that controls flow by means of a disk or wedge-shaped

dam sliding at right angles to the direction of flow and seating

tightly in the valve body is a

gate valve butterfly valve

2 The friction factor for flow through a pipe with relative roughness

of 0.004 at a Reynold's No. of 80,000 is approximately equal to

0.052 0.025

3 The equation that relates friction factor and Reynold's No.,

f=64/Reynold's No. holds for

smooth pipes laminar and

turbulent flow

4 Oil flows under laminar conditions inside a steam heated copper

pipe. The overall heat transfer coefficient is approximately

equal to the

heat transfer

coefficient of

the oil

the average

between the

heat transfer

coefficient of the

steam and that

of oil

5 In multi-stage liquid-liquid extraction with partially miscible

solvents

the extraction

must be done

to form co-currently in

order to

minimize the

extraction.

the minimum

number of

stages occurwhen the

operating lines

are parallel.

6 The enrichment of the vapor steam as it passes through the

column in contact with the reflux during distillation is called

evaporation stripping

7 The maximum number of plates for a given distillation system is

obtained at

variable reflux maximum reflux

8 The correct unit for the specific rate constant for the reaction A---

>B determined to be first order is

square

liter/square

mol/min

square

liter/square

mol/square min

9 On one side of a heat exchanger where either a condensing

vapor or a boiling liquid is present, the temperature may be

assumed to be constant. In determining the logarithmic mean

temperature difference the direction of flow will have

large effect little effect

10 For a cylinder where steady-state radial heat transfer takes place the heat flux is

constant

maximum heat

transfer rate

occurs at the

surface

11 A plate holding a pool of liquid from which rises a vapor whose

average composition is in equilibrium with a liquid whose

composition is the average of that of the liquid leaving the plate is

called

separation

plate

theoretical plate

12 Crystallization occurs in a solution that is concentrated unsaturated13 Mass transfer in a flowing fluid may be correlated by Sherwood,

Nusselt and

Reynold's No

Peclet,

Reynold's and

Schimdt No

14 The ratio of the average diameter of the feed to the average

diameter of the product is the

settling ratio discharge ratio



15 The rate of formation of C for the reaction 2A + B ---> C is found

to be rate=k(A)(B)

the rate of

formation of C

is equal to the

rate of

disappearance

of B

the order of

reactio is zero

16 A device for increasing the velocity of a fluid in steady flow is a nozzle vent

17 In steady-state backmix flow reactor, composition is not constant

throughout the

reactor

constant

throughout the

reactor

18 The amount of money obtainable from the sale of used property

over and above any changers involved in removal and sale is

called

net value salvage value

19 In fractionation, an increase in reflux ratio increases the

number of

theoreticalplates

decreases the

reboiler duty

20 In mass transfer where the solute in the gas phase is very

soluble in the liquid phase

the ratio of

liquid phase

resistance to

the overall

resistance is

close to unity

the gas phase

resistance is

approximately

equal to the total

resistance

21 Heat transfer in turbulent flow may be described through an

empirical equation correlating

Nusselt,

Stanton and

Reynold's Nos

Nusselt, Prandtl

and Reynold's

Nos

22 Which of the following fittings exhibits the highest pressure drop

for the same flow conditions?

90-degree long

radius elbow

90-degree

standard elbow

23 A chamber into which steam from a high pressure line can be

bled during periods of low steam demand from the power plant is

called

switching bank vent

24 Which one of the following pipes has the highest relative

roughness?

2" diameter

Wrought iron

pipe

4" dia Wrought

iron pipe

25 In steady-state heat transfer through a series of materials with

varying resistances, the heat transfer rate

decreases

towards the

direction of

heat transfer

varies with the

thermal

conductivity of

each material

26 Reactions whereby reactants proceed along several paths and

give different products are

polymeric

reactions

reversible

reactions

27 Which one among the following materials has the best insulating

property?

window glass wood

28 An operation where warm vapor mixture is cooled such as by

contact with a liquid resulting in condensation and decreased

humidity is

evaporation dehumidification



29 The pressure exerted on a plane parallel to the direction of flow

of a moving fluid is called

gauge pressure velocity pressure

30 For mass transfer to take place, there must be a phase change reaction

component

31 Water vapor condenses at 1 atm on a tube whose surface

tmeperature is at 80 deg F. in analyzing the heat transfer through

the condensate film, it is best to evaluate the liquid properties at

212 deg F 80 deg F

32 The diffusity of water in air at 100 deg F in sq.cm./sec is 0.256 0.278

33 A fluid flowing at a rate of 25 cubic meters per hour inside a 60

mm I.D. pipe has an average velocity in meter per sec equal to

5.9 2.5

34 An equimolar mixture of benzene and toluene is subjected to a

single batch distillation. Distillation is discontinued when 60% of

the benzene in the feed is distilled. At this instance the bottom

product when analyzed shows benzene to be 36.4 mole%. In the

distillate, the mole% of benzene is

66.6 58.1

35 When 32 kg of methane is burned completely the theoretical

oxygen required is

16 kg 64 kg

36 The standard heat of reaction for the production of water gas, in

kcal/gmole, as given by the equation: C(s) + H2O(g) = CO(g) +

H2(g) is

32.2 31.4

37 A rectangular duct 4 ft x 1.5 ft in cross section carries conditioned

air. In determining the pressure drop through the duct the

equivalent diameter in ft may be used which in this case is

4 2.18

38 A gas decomposition reaction has an activation energy of 245

kJ/mol. The rate of reaction can be accelerated by using a

platinum catalyst where the activation energy for the resulting

catalyzed reactions is lower at 136 kJ/mol. Using Arrhenius' law

and assuming the frequency factor remains the same the

catalyzed reaction is faster than the original reaction by a factor

of

over 100,000

but less than a

million

over 100 but

less than 200

39 Water at 100 deg F is flowing through a straight 4-in Sch 40 pipe

at a rate of 1.0 gal/min. The length of the pipe is 10 ft. The

velocity at the center of the pipe in ft per sec is

0.0378 0.0504

40 A metallic rod 2 cm in diameter is used as a heating element.

The thermal conductivity is 370 J/sec.sq.m.degC. The surface

temperature is maintained at 200 deg C. For the center of the rod

not to exceed 500 deg C, the maximum volumetric heat

generation rate within the metallic rod in J/sec cu.m. must be

4440000 5130000

41 This is a steady state temperature reached by a small amount of

liquid evaporating into a large amount of unsaturated vapor-gasmixture.

wet-bulb

temperature

dew point

42 Air, supplied at the rate of 1200 cfm to a refrigerated coil, has a

relative humidity of 20% and dry bulb temperature of 150 deg F.

The mass flow of dry air entering per minute is

74.3 75



43 In adiabatic humidification, it is possible to maintain the

temperature of water constant since

according to

the phase rule,

the degrees of

freedom is 3

the system can

be well insulated

from the

surroundings

44 An air-carbon tetrachloride vapor mixture at 100 deg F dry bulband 60 deg F wet bulb is heated until the temperature reaches

180 deg F. the final percent relative humidity is about

0.1 0.05

45 The portion of water in the wet solid that cannot be removed by

the air in its contact is called

free moisture final moisture

content

46 This type of drier is used for drying pasty materials such as wet

filter cakes and lumpy solids

rotary drier flash drier

47 In the constant-rate period, the rate of drying is established by a balance of

the heat

requirements

for evaporationand the rate at

which heat

reaches the

surface

the internal

movement of

moisture

beneath thesurface of the

solid

48 Unbound moisture in granular and porous solid moves through

the intertices of the solid by a mechanism involving

desorption surface tension

49 Wet solid is to be dried from 40% to 10% in 5 hours under

constant drying conditions. The critical moisture content is 20%

and the equilibrium moisture content is 7%. All moisture contents

are on dry basis. The time needed to dry from 15% to 5% free

moisture under the same drying conditions is

0.542 hrs 1.846 hrs

50 If the rate of drying under constant drying conditions with air at

140 deg F and absolute humidity of 0.03 lb water per lb dry air of

unknown mass of solid is given by R=0.5-exp(-60X) [in lb

water/hr-sqft], then the equilibrium moisture content (db) of the

material is

0.12 0.034

51 In drying at the falling rate period, the rate at which moisture is

removed from the solid material

remains

constant

increases with

time

52 The major problem in diffusion is to promote diffusion of the

solute out of the solid and into the liquid. The most effective way

of doing this is

to reduce the

solid to the

smallest size

feasible

to use counter

current

operation

53 A slurry flaked soybeans weighing 100 kg contains 75 kg inert

solids and 25 kg of solution 10 weight % oil and 90% wt solventhexane. This slurry is contacted with 100 kg pure hexane in a

single stage so that the value of retention for the outlet underflow

is 1.5 kg of insoluble solid per kg solvent in the adhering solution.

The composition of underflow leaving the extraction stage in %wt

oil is

0.3 0.8



54 Tung meal containing 55% oil is to be extracted at the rate of

4000 lb per hour using n-hexane containing 5% oil as solvent. A

countercurrent mulitple stage extraction system is to be used.

The meal retains 2 lb of solvent per pound of oil free meal while

the residual charge contain 0.11 lb oil per lb oil free meal while

the product is conposed of 15% oil. The theoretical number of

ideal stages is

3 4

55 The movement of molecules over a substantial distance is

associated with the transfer of heat by

convection conduction

56 The mode of heat transfer that can take place in a vacuum is

known as


57 The overall conductance for a composite material in series is

equal to the

sum of the

individual

conductances

sum of the

individual

conductivities

58 Film and drop are terms associated with boiling condensation

59 A 6-in Sch 80 steel pipe is carrying glycerin at an average

temperature of 100 deg F. The pipe is uninsulated, and the

outside temperature is 30 deg F. The inside film conductance is1000 Btu/h-ft-degF while the outside film conductance is 3.0

Btu/h-sq.ft.-degF. Determine the heat lost [Btu] per minute from a

75-ft length of the pipe. Glycerine is flowing at 800 gpm.

99.95 415.7

60 An oak (k=0.096 Btu/h-ft-degF) door, 30 in wide, 78 in high, and

2 in thick, has 9 glass (k=0.45 Btu/h-ft-degF) windows, each 6 in

by 8 in by 1/4 in thick. Determine the amount of heat lost [Btu]

each day with a surface-to-surface temperature difference of 80

deg F.

97 242

61 Determine the length needed for a simple concentric-tube,

parallel flow heat exchanger to transfer heat from hot water to

cold water at a rate of 900 W. The heat exchanger consists of

two Type K copper (k=386 W/m-degC) tubes. The smaller tube

has an inside diameter of 49.8 mm and an outside diameter of

54.0 mm. Assume that both film coefficients are equal to 100

W/sq.m.-degC. The hot water enters at 90 degC and leaves at

50 degC, and the cold water enters at 10 degC and leaves at 40

degC.

185.5 m 11.02 m

62 A saturated solution containing 1500 kg of potassium chloride at

360 K is cooled in an open tank to 290K. If the specific gravity of

the solution is 1.2, the solubility of potassium chloride per 100

parts of water is 53.55 at 360K and 34.5 at 290K, calculate the

amount of crystals obtained assuming that loss of water by

evaporation is negligible.

4301 kg 1500 kg

63 An evaporator, working at atmospheric pressure, is toconcentrate a solution from 5% to 20% solids at the rate of 1.25

kg/s. The solution which has a specific heat of 4.18 kJ/kg-K is fed

to the evpaorator at 295K and boils at 380K. Dry saturated steam

at 240 kPa is fed to the calandria and the condensate leaves at

the temperature of the condensing steam. If the heat transfer

coefficient is 2.3 kW/sq.m-K, what is the required area of heat

transfer surface. The latent heat of vaporization maybe taken as

the same as that of water.

55.8 sq.m. 58.5 sq.m.



71 How many cu.ft. per minute of entering air is needed to

evaporate 10 lb of water per hour from a rayon, if the air enters at

80 deg F and 25% humidity and leaves at 170 deg F and 55%

relative humidity. The operating pressure is 14.3 psia.

12.54 12.68

72 Nicotine is to be extracted from water using kerosene. If 100 lb of

a 2% nicotene solution is extracted once with 200 lb of kerosene,what percent of the nicotene is extracted? {Equilibrium data: Y[lb

nicotene/lb kerosene] = 0.90X [lb nicotene/lb water]}

64.5 54.6

73 We must cool 2500 gpm of water from 120 to 80 deg F. A cooling

tower, at 70 deg F and 1 atm, is to be designed to operate with

entering air of 40% relative humidity. How many gpm of makeup

water must be supplied if windage loss is 95% of the amount lost

by evaporation.

77.2 150

74 We wish to build an economical cold room 20 ft square and 10 ft

high. The outside temperature is 80 deg F and te room is to be

maintained at 0 deg F. The boss has suggested parallel wooden

outer and inner walls separated by a 6-in air space. What will bethe heat loss [Btu/hr] through each wall?

3537 8457

75 A colloidal solution is to be concentrated from 15 to 65% solids.

The specific heat of the feed, entering at 50 deg F is 0.93. The

pressure of the saturated steam to the evaporator is 10 psia; the

condenser pressure is 5-in. Hg abs. The steam chest has an

overall heat transfer coefficient of 200 Btu/hr-sq.ft.-degF. Water

must be evaporated at the rate of 35,000 lb/hr. Neglecting boiling

point elevation, what is the steam consumption [lb/hr]?

10500 35000

76 What is the settling time [sec] for galena particles to settle under

free settling conditions through 5 ft of water at 50 deg F. Galena

is spherical in shape, with specific gravity and 0.01 inch in

diameter.

38.1 18.3

77 A 10-ft diameter tank with a quick-opening value to a sump has a

10-ft depth of liquid. How long [t in sec] does it take to drain the

tank if the valve is assumed to be equivalent to a 4-in diameter

orifice? The liquid density is 60 lb/cu.ft.

2951 1644

78 What size sharp-edged orifice [inches] was in use if a flow of 120

gpm produced a 4-in Hg differential in a 4-in Schedule 40 pipe.

The fluid, measured at 60 degF, had a viscosity of 1 cSt and a

specific gravity of 1.

2.21 1.35

79 Seven hundred gallons per minute of water are being discharged

by a centrifugal pump 5 ft above the pump inlet. The inlet

pressure is 4-in Hg above atmospheric and the discharge

pressure is 29 psia. If the pump has an 8-inch diameter inlet anda 4-inch diameter discharge, calculate the pump efficiency.

63 84



80 Determine the net positive suction head available to a centrifugal

pump when the level of water is just at the suction point. The

pumped fluid is water at 140 deg F and it is pumped from an

atmospheric tank at 250 gpm. The tank suction point is 7 ft

above the pump. The piping is 5-in Schedule 40, 10-ft long with

two short radius 90 deg elbows. [Use density=61.38 lb/cuft,

Pv=2.89 psi, viscosity=0.47 cP]

34.2 27.7

81 Water at 60 deg F flows through a 3-inch Schedule 40 pipe. A

pitot tube in the pipe shows a 3-inch Hg differential. If the pitot

tube is located at the center of the pipe, what is the mass flow

rate of the water [lb/s]?

11.61 14.24

82 The gas phase irreversible reaction A+B---->C is elementary.

The entering flow rate of A is 10 mol/min and is equal molar in A

and B. The entering concentration of A is 0.4 mol/L. What CSTR

volume [L] is necessary to achieve 90% conversion?

113 227

83 The irreversible zero order gas phase dimerization 2A ----->A2

is carried out in a packed bed reactor with 5 kg of catalyst. The

entering pressure is 10 atm and the exit pressure is 1 atm. Pure A enters at a flow rate of 10 mol/min. The reaction is zero order

in A. What is the exit conversion?

0.15 0.5

84 The gas phase reaction 2A+B----->C is carried out in a PFR. The

feed is equal molar in A and B and the entering temperature is

500K and the entering pressure is 16.4 atm. If the exit conversion

is x, then the exit concentration of B is

[B]=0.4(1- x )/(1-

0.5 x )

[B]=0.4(1- x )/(1-

1.5 x )

85 Heat is generated in a 2.5 cm square copper rod at the rate of

35.3e6 W/cu.m. The rod is exposed to a convection environment

at 20 deg C where the convection heat transfer coefficient is 4

kW/sq.m.-degC. Determine the surface temperature [deg C] of

the rod.

75.2 55.2

86 A 5cm diameter cylinder is maintained at a constant temperature

of 200 deg C and it is "completely enclosed" by a wind tunnel test

chamber, walls of which are at 10 deg C. Air at 350K is forced

across the cylinder at a velocity of 50 m/s (h=180 W/m-degC). If

the surface emissivity of the cylinder is 0.7, determine the total

(i.e., convective and radiative) heat transfer from the cylinder [W

per meter length].

13 272

87 A building wall consists of a 6-in of concrete (kc= 0.7 Btu/hr-ft-

degF), 2 in of fiber insulating board, and 3/8 in of gypsum board

(kg=0.03 Btu/hr-ft-degF). The inside and outside heat transfer

coefficients are 2 and 7 Btu/hr-sqft-degF, respectively. The inside

temperature is 72 degF and the outside temperature is 20 degF.

Determine the overall heat transfer coefficient for this wall [Btu/hr-sqft-degF].

0.028 0.119

88 Current is passed through a cylindrical laboratory heater, which

has a 3 cm diameter, generating heat at the rate of 20 MW/cu.m.

The heater is exposed to a convection environment at 25 degC

where the convection heat transfer coefficient is 0.5 kW/sq.m.-

degC. Determine its surface temperature [degC].

325 300



99 The material which remains unchanged in a process is limiting reactant tie substance

100 The ratio of the total quantity of a reactant present in the reactor

feed of a recycling operation to the quantity of the same reactant

entering the operation as fresh feed is the

recycle ratio combined feed

ratio

101 The heating value measured when water formed from

combustion is in the liquid state.

Gross Calorific

Value

Heat of

combustion102 In the combustion of solid fuels, the tie element between the feed

and the refuse is the

cooked coal ash

103 The coal analysis which is based upon the volatilization

characteristics of the fuel is

Proximate

analysis

Modified

analysis

104 An Orsat analysis of the flue gas when pyrite is roasted is on a SO2-free basis SO3-free basis

105 The empirical relation which allows one to compute for the net

hydrogen in a given solid fuel is the

Calderwood

equation

Theoretical

Oxygen

Equation

106 The equivalent of 45degTw in the Baume scale is 26.63 28.32

107 A furnace completely burns coal containing 70%C. Analysis ofthe flue gas shows 15% CO2, 4% O2, 81% N2, and no CO.

What is the % of the net hydrogen in the coal?

1.2 1.53

108 Which has the lowest water content? dew point at

20degC

70% RH

109 A contract was made between a buyer and a paper manufacturer

for paper containing 5% moisture at PhP450/tonne FOB on

specifications that price adjustment will be made if the quality is

different. How much should the buyer pay for 1 tonne of paper

with 8% moisture content? Freiht cost is PhP45/tonne.

PhP 405 PhP 424.26

110 One drier will dry a material from 45% moisture (wb) to 20%

moisture (db). From here the material enters another drier where

the water content is further reduced to give a final product

weighing 1000 kg. If the total evporation from both driers is 800

kg, the moisture of the final product is

0.01 0.02

111 An experimental oil is used to distill 6000 kg.hr of Athabasta tar

sand which analyzes 30% 'heavy oil', 'light oil', and non-volatile

matter. If the distillate contains 12 % heavy oil and this

constitutes 25% recovery of the component, the weight in kg of

the distillate obtained is

2250 3750

112 Coal fired in a furnace has a heating value of 13800 Btu/lb and

contains 78.05%C and 1.2%S. The proximate analysis shows

4%M, 24%FC, 8%A and the analysis of the refuse shows

8%VCM, 25%FC and 32% ash. Calculate the % of C lost in therefuse.

4.22 8

113 Ninety grams of ethane and 384 grams of oxygen are fed

continuously to a laboratory furnace. The total combustion

products collected was 16.2 gmole with no carbon dioxide.

However, not all of the ethane was burned due to faulty

combustion. The fraction of ethane that was burned is equal to

0.8 0.85



114 The furnace at the Bataan refinery is using a fuel gas which

contains methane, ethane and 20% nitrogen. The orsat analysis

of the combustion products showed 7.8% CO2, 7.4% O2, and

84.8% N2. The gas is burned with excess air. The % methane in

the fuel gas is

63.25 57.24

115 Pyrite containing 78% FeS2 and 22% gangue is burned with

excess air to produce a stack gas with the following analysis:7.29% SO2, 8.92%O2, 82.44%N2 and 1.35%SO3. If the cinder

was found to have a partial analysis of 62.10% Fe2O3, the % of

FeS2 lost in the pyrite is

3.52 6.53

116 The unit of k for a 1st order elementary reaction is 1/time conc/time

117 If the temperature of a chemical reaction is raised by 10 degC,

the rate of reaction is increased by a factor of

4 3

118 The E of a reaction may be lowered by increasing

temperature

decreasing

temperature

119 The mechanism of a reaction can sometimes be deduced from the activation

energy

the temperature

dependency of

the rate120 The equilibrium constant in a reversible chemical reaction at a

given temperature

depends on the

initial conc of

the reactants

depends on the

conc of one of

the products at

equilibrium

121 If the volume of a reaction vessel is suddenly reduced to one half

its original volume the rate will increase by a factor of

2 4

122 The rate of reaction is not influenced by conc of the

reactants

molecularity of

the reaction

123 The net rate of reaction of an intermediate is 0 2

124 A reaction is known to be first order in A. A straight line will be

obtained by plotting

log Ca vs time Ca vs time

125 If the reaction 2A ---> B+C is second order, which of the following

plots will give a straight line?

Ca^2 vs time 1/Ca vs time

126 For the reaction A+B ---> 2C, when Ca is doubled the rate

doubles, when Cb is doubled the rate increases fourfold. The

rate law is

-ra = k Ca^2

Cb^4

-ra = k Ca Cb^2

127 It states that the rate of a chemical reaction is proportional to the

activity of the reactants.

Le Chatelier's

principle

Hess' Law

128 The half life of a material undergoing second order decay is proportional to

the square of

the initial conc

independent of

initial conc

129 A fluid flows through 2 CSTR in series. Each reactor has a

capacity of 400,000 L and the fluid enters at 100 L per hr. The

fluid undergoes a first order decay with a half life of 24 hours.

Find the conversion of the fluid.

66.8 74.7

130 A first order reaction has a specific rate constant of 3e-3 per sec.

The half life is

0.0021 s 100 s

131 A certain reaction is 1st order in A. In 30 min, the concentration

of A decreases from 0.55 to 0.15 mol/L. The time it will take for A

to decrease from 0.35 to 0.15 mol/L is

45.1 min 19.6 min



132 A gas decomposes at 900 degC according to 2A--->2R+S with a

rate constant of 1000 cc/gmol-s using pure A. The time it will take

to react 80% of A in a batch reactor at 900 degC and 1 atm in

min is

3.83 7.43

133 Calculate the length of a chlorinating pipe line with diameter of

0.6 m required to kill 95% of the bacteria in waste water flowing

at 0.05 cu.m/s. Test shows that 95.33% kill is obtained in 5minutes when treated with 5 mg/L of chlorine. Chlorine

disinfection kinetics is given by the equation: dC/dt = k Ct^1.5

where C = number of bacteria. Assume that the same

concentration of chlorine is used in actual treatment operation.

25.36 m 32.5 m

134 The set of data given below is for the parallel reaction: a---k1--

>2R, a---k2-->S. At t=0, Ca=15 moles/cuft, Cr = 1 mole/cuft,

Cs=1 mole/cuft; At t=1 hr, Cro = 9 moles/cuft, Cs = 3 moles/cuft.

The value of K2 per hour is

0.1697 0.183

135 A batch reaction 2D+E----->F has a conversion factor expressed

by the equation r =0.24 t^0.5 where r = conversion factor based

on the reactant E; t = time in hours which ranges from 0.5 to 16hours per batch depending upon the process variables. The

average molecular weight of the feed is 60 and a density of 1.4

g/cc. The feed consists of 2 kgmole of D and 1 kgmole of E. The

charging, cleaning and discharging time per batch is 2.5 hrs and

the volume of the reactor is twice the volume of the feed.

Assume 300 days per year and 12 hours operation/day. The

volume of the reactor in liters is

257 275

136 A container holds 100 gal of salt solution containing 50 lb of

dissolved salt. The bottom of the container is covered with a layer

of rock salt. The bottom of the container is covered with a layer of

rock salt whose surface is practically constant. The salt dissolved

into the solution according to r = k(C-3) where C is the

concentration of the brine expressed in lb/gal. If the water in the

tank were fresh, the rate of solution would be 1.0 lb/min. Fresh

water enters at 3 gpm and brine overflows at the same rate.

Assume constant volume at any brine concentration, the

concentration of brine in container after 1 hour in lb/gal of salt is

0.732 0.427

137 An aqueous solution of ethyl acetate is to be saponified with

NaOH. The initial concentration of the ethyl acetate is 5 g/L and

that of the caustic soda is 0.10M. Values of the second order rate

constant in L/gmole-min are k = 23.5 at 0 degC; k = 92.4 at 20

degC. The reaction is essentially irreversible. The time required

to saponify 95% of the water at 40 deg C is

10.3 11.4

138 At 500K the rate of bimolecular reaction is 10 times the rate at

400K. Find E in cal, the activation energy for this reaction from

Arrhenius Law.

8150 9150

139 The reaction A+2B--->R is 1st order with respect to each

reactant. If equimolar amounts of A and B are introduced into a

constant-volume reactor and (1/m) th of A remains after t1, how

much will remain after t2=2t1?

Cao/2m Cao/(2m-1)



140 When the 1st order homogeneous reaction (gas-phase) A---

>2.5R is carried out in an isothermal batch reactor at 2 atm with

20% inerts present, the volume increases by 60% in 20 min.

When the reaction is carried out in a constant volume reactor,

the time required for the pressure to reach 8 atm if the initial

pressure is 5 atm, 2 atm of which consist of inerts in min is

43.1 41.3

141 When the ID of the pipe through which a fluid flows is doubled,

the pressure loss due to friction per unit length of pipe and for the

same volumetric flow rate is changed by approximately a factor

of

1/8 1/16

142 When two centrifugal pumps are connected in series, the

discharge changes by a factor of

1/2 1

143 When two reciprocating pumps are connected in parallel, the

volumetric capacity of the system changes by a factor of

1/2 1

144 The pressure drop in a pipeline changes by a factor of _____

when the velocity of the flowing fluid is doubled.

1/2 1

145 Cavitation occurs in a centrifugal pump when the discharge

pressurebecomes too

high

the discharge

valve is closed

146 Oil with a viscosity of 30 cP and a density of 60 lb/cu.ft. f lows

through a 1/2-inch inside diameter pipe. Determine the velocity in

fps below which flow will be laminar.

0.63 13.1

147 Water at 60 deg F flows through a 3-inch inside diameter smooth

horizontal pipe. If the Reynold's number is 353000, calculate the

ratio of maximum velocity to average velocity.

1.05 1.22

148 The pressure after the pump in a 6-inch inside diameter smooth

pipe conducting water is 20 psia. The water is discharged at an

open tank 100 ft from the pump. Calculate the rate of discharge

of water in cu.ft/s.

0.6 3.58

149 A water storage tank assumes the supply of water into a factory.

Water is supplied to the tank through a booster pump installed in

the water line. The theoretical pump horsepower required is 3.25

hp. What is the monthly operating cost of the pump if electric

power cost on the average is PhP 3.73/kWh. The pump is 65%

efficient and operates for 12 hr a day.

PhP 3300 PhP 5000

150 When the impeller speed of an ideal centrifugal pump is doubled,

the vol. flow rate of discharge is increased by a factor of

1/2 1

151 The differential height between two points which a fluid has to be

transferred is the

potential head pressure head

152 The resistance of a layer of fluid to flow over the next layer ismeasured by

viscosity friction factor

153 An axial flow pump operating at a speed of 880 rpm can supply

water at a rate of 3000 gpm. The maximum head that this pump

can deliver in ft. of water is

20 36

154 Specify the type of open impeller pump to use if the capacity is

400 gpm at a head of 200 ft of water.

3x2x8.5E 4x3x8.5E



155 What will be the rated capacity [gpm] of a 4-1/2 inch impeller

centrifugal pump operating at a speed of 3450 rpm capable of

generating a head of 40 ft of water.

95 134

156 If the speed of a centrifugal pump is doubled, the energy

requirement becomes approximately ___ times the original

energy requirement.

2 4

157 A cylindrical tank 1 ft in diameter discharges through a nozzleconnected to the base. Find the time needed for the water level

in the tank to drop from 4 ft to 2 ft above the nozzle. The

diameter of the nozzle is 1 inch and its discharge coefficient

maybe taken as unity.

32 55

158 The NPSH of a single suction centrifugal hot water pump at a

speed of 3550 rpm operating at a pressure of 600 psi and a

capacity of 450 gpm is ___ ft.

15 20

159 The rate of evaporation at a given operating temperature in a n

evaporator is more when

when the

operating

pressure is high

the operating

pressure is low

160 An optimim number of the effects for a given application is afunction of the capacity economy

161 A popular type of heat exchanger for cooling large quantities of

fluid is the

double-pipe plate

162 An evaporator is used to concentrate 10,000 lb/hr of a 20%

solution of NaOH in water at 140oF using saturated steam at 25

psia at a rate of 7,000 lb/hr. The OHTC is 275 BTU/hr-ft2-oF

when the pressure in the vapor is 1.7 psia. The steam economy,

SE, is

0.82 0.863

163 A cross flow heat exchanger uses mixed air at 4 kg/s that enters

at 15oC and leaves at 45

oC. The air cools unmixed water, which

enters at 95oC and 0.70 kg/s. The OHTC equals 150 W/m

2-oC.

After several months of operation, a scale resistance of 0.002 m2-oC/W developed. 16. The heat transfer area required to

accom lish the chan e is

22.2 m2

25 m2

164 As solution of 28% wt Na2SO4 is to be crystallized to yield

Glauber salt in a four section (one section is 10 ft in length)

Swenson Walker Crystallizer. It is fed to the unit at 120oF and

cooled to 60oF using cooling water which enters at 50

oF and

leaves at 70oF. The crystallizer has a cooling surface of 3 ft

2 per

foot of length. The feed rate is 500 lb/hr and the crystallizer is

seeded with 50 lb/hr of 65 mesh crystals. 19. The amount of the

crystalline crop (C) produced in lb per hour is

285.3 249.3

165 An insulator should have low thermal

conductivity

high thermal

conductivity

166 Fouling factor is a

dimensionless

quantity

does not provide

a safety factor

for design



186 Which of the following processes may always be regarded as a

constant- humidity process?

cooling of air air conditioning

187 Air conditioning in tropical countries involves humidification

by a process

similar to that in

a cooling tower

humidification by

a process

similar to air-

water vaporsaturator

188 What do you call the steady-state non-equilibrium temperature

reached when a small amount of water is contacted under

adiabatic conditions by a continuous stream of gas?

dry-bulb

temperature

wet-bulb

temperature

189 The moisture content of a solid is given as 50% wet basis. What

is the moisture content, dry basis?

0.5 1

190 The moisture that can be removed by drying is called equilibrium

moisture

bound moisture

191 Falling-period in drying terminates at the end of constant-

rate period

origin of R vs X

plot

192 Which is not true at the interphase of a gas scrubbing operation? the solute

concentration

of the gas is

less than that of

the bulk

the solute

concentration of

the liquid is less

than that of the

bulk

193 He and N2 gas are contained in a conduit 5 mm in diameter and

a 0.1 m long at 298 K and a uniform pressure of He at one end of

the tube is 0.6 atm and 0.02 atm at the other end. Assuming

equimolar countercurrent diffusion, the flux in kmol/s-m2 is

2.35 exp-5

2.44exp-5

194 100 m3/hr of air at 60C and 20% RH is needed for a chemical

reactor. This will be obtained from process air at 60C and 10%RH by humidifying adiabatically the process air followed by

heating to its original temperature. The wattage of the heater at

80% efficienc is

5280 8490

195 Wet solid is to be dried from 36% to 8% moisture in 5 hr under

constant drying condition. Critical and equilibrium moisture

contents are 14 and 4% respectively. Calculate how much longer

will it take to dry the same material from 8% to 5.5% moisture

under constant drying condition. All moisture contents are on a

dry basis.

1 hr 1.6 hr

196 The unit of volumetric diffusivity is cm^2/sec cm/sec

197 If reflux to a distillation column is 100 moles/hr, when the

overhead product rate is 50 moles/hr. the reflux ratio is

0.5 2

198 Which of the following provides maximum contact surface for a

liquid-vapour system?

packed lower bubble-cup plate

column

199 In extraction, as the temperature increases, the area of

heterogeneity (area covered by bimodal curve)

decreases increases

200 The suitable evaporator for concentration of foaming liquids is long tube

evaporator

short tube

evaporator

201 Macroscopic transfer of mass between moving fluid and surface

which is of different concentration is called

molecular

diffusion

unsteady-state

diffusion



202 For a packed column the main purpose of packing is to strengthen the

column

increase the

surface area

203 In a gas absorption operation, when the operating line crosses

the equilibrium curve

the NTU is zero the liquid flow

rate is maximum

204 Methanol diffuses in 0.15 cm stagnant film of 1:1 mole mixture of

hydrogen and CO2 at 100oC and 2 atm. The partial pressures of

methanol on both sides are 0.6 and 0.2 atm. The average

diffusivity of methanol in the hydrogen and CO2 at 0oC and 1 atm

in cm2/s is

0.15 0.31

205 Gaseous reactant A decomposes according to the reaction A -->

3R (-r A = 0.5 C A mole/L-min). The feed, which consists of 70% A

and 30% inert, enters a 1.5-m3 CSTR at a flow rate of 150 L/min.

4. If CA0 = 0.30 mole/L, what is the conversion, XA?

0.92 0.86

206 Between 0 degC and 50 degC, the average activation energy of a

certain reaction is 80 kJ/mol. How many times faster will the

reaction occur at 300 K than at 275 K?

14.7 18.5

207 Consider a gas-phase reaction 2A ---> R + 2S with unknown

kinetics. A space velocity of 0.8/min is needed for 95%

conversion of A in a PFR. Find the mean residence time or

holding time of the fluid in the PFR.

0.54 min 0.85 min

208 For Newtonian fluids, the shear stress is constant. inversely

proportional to

rate of

deformation.

209 An ideal fluid is one that is compressible incompressible

& viscous

210 Water flows through an 8-in (ID=7.981 in) steel pipe at anaverage velocity of 6 ft/s. Downstream the pipe splits into an 8-in

main and a 2 in (ID=2.067 in) bypass pipes. If the velocity in the

bypass is twice the velocity of the main pipe, the volumetric flow

rate [ft3/s] in the main pipe is

10.58 5.29

211 An imaginary line within a fluid flow such that a tangent at any

point indicates the direction of flow at that point.

stream tube velocity profile

212 Air at 250C [viscosity=0.018 cP] enters a section of 2-in schedule

40 commercial steel pipe at a gauge pressure of 310 kPa and a

flow rate of 1200 kg/h. Assuming isothermal flow, what is the

pressure drop [kPa] in 60 m of pipe?

350 155

213 A simple pitot tube measures acoustical

velocity

superficial

velocity214 Which of the following meters will have the highest permanent

pressure loss?

pitot tube orifice

215 In the flow meter equation, Y, indicates the mass flow rate compressibility

factor

216 The loss due to sudden contraction is proportional to velocity turbulence

217 Stoke’s law is valid when the particle Reynolds number is < 1 > 1

218 Priming needed in a Reciprocating

pump

Gear pump



219 Maximum theoretical suction lift for water at 60˚F by a centrifugal

pump is 34 ft. The same for water at 200˚F will be

40 ft 37 ft

220 The most economical valve for use with large diameter pipes. butterfly globe

221 Multistage compressors are used in industry because, they reduce the cost

of compressor

reduce the size

requirement

222 For ideally incompressible fluid, the mach number will be 0 1

223 of the following produces maximum pressure difference for

transportation of gases?

vacuum pumps blowers

224 The fluid property which matters for falling rain drops to acquire

spherical shape is its

pressure height of

descend

225 A wastewater solution having a volume of 1000 L contains 0.21

kg phenol/m3 of solution. A total of 1.40 kg fresh granular

activated carbon is added to the solution, which is then mixed

thoroughly to reach equilibrium. What is the amount of phenol

absorbed per kg carbon at equilibrium?

0.007 kg 0.106 kg

226 The overhead product composition decreases with time in batch distillation

with reflux

continuous

distillation withreflux

227 For a binary mixture with low relativity, continuous rectification to

get pure products will require

low reflux ratio small cross-

section

228 Chemisorption is the same as

van der Waals

characterized by

adsorption of

heat

229 The stage efficiency in leaching depends on the time of contact

between the

solid and the

solution

rate of diffusion

of the solute

through the solid

and into the

liquid

230 Weeping in distillation or absorption column increases tray

efficiency

provides larger

surface for mass

transfer

231 What are the two contacting phase in leaching? extract phase

and raffinate

phase

solvent phase

and solute

phase

232 Hydrogen sulfide is removed from water by contacting the

solution with warm air. The operation is

Distillation Leaching

233 Disregarding the cost, which is the best solvent for the extraction

of acetic acid from an aqueous solution at 25deg C?

caproic acid chloroform

234 Professional Regulations Commission was created under P.D. No. 223 P.D. No. 233

235 A chemical engineer who designed and built a new type pf

reactor and for three years, sold many units to the public can stillpatent his reactor.

TRUE FALSE

236 A person who has passed the Chemical Licensure Examination

can take his/her oath as a chemical engineer if his/her age is not

less than _______ years.

18 19

237 Which of the following is not a requirement for utility model

registration?

inventive step novelty



238 A section of the patent application containing detailed

descriptions of the benefits obtained from using the invention is

called the

disclosure abstract

239 A document issued by the DENR secretary indicating that the

proposed project will cause significant negative environmental

impact.

Environmental

Impact

Statement

Environmental

Compliance

Certificate

240 In the Philippines, sulfur for sulfuric acid manufacturing issourced from _______ industry.

paper cement

241 Sulfur is undesirable in petroleum because it causes

engine

knocking

it increases the

boiling pt of fuel

242 Materials added to detergent formulation to enhance cleaning

performance by exhibiting synergistic cleaning effect with

surfactant.

fillers brighteners

243 Polyethylene is an example of _____________ polymerization condensation addition

244 Principal chemical conversion in the production of resin from

monomer.

condensation hydration

245 Carbon black is added to rubber compounding as activator curing agent

246 The binder for all the powder materials of paint pigment vehicle

247 A fibrous material left after cane sugar has been milled is

commonly called as

bagasse pulp

248 Molasses is a by product of raw sugar from the ______ process milling extraction

249 Kraft process is a common name for sulfate pulping sulfite pulping

250 Water insoluble cell binders of wood pulp cellulose

251 DDT means Diphenyldichlor

otriphenylethan

e

dichlorodiphenyl

dichloroethane

252 Rancidity of oil can be reduced by decoloration hydrogenation

253 Varnish does not contain pigment dryer

254 Plasticisers are added to paints to make it

corrosion

resistant

make glossy

surface

255 Silicone is thermoplastic a monomer

256 The process involved in converting rubber into a thin sheet or

coating it on fabric is called

extrusion mastication

257 Alkyl benzene sulfonate (ABS) is a detergent rubber

258 Neoprene is a monomer synthetic rubber

259 Steam enters an adiabatic turbine at 10 MPa and 500 deg

C at a

rate of 3 kg/s and leaves at 0.1 MPa. If the power output of the

turbine is 2 MW, determine the turbine efficiency.

0.2348 0.3216

260 Work is a property of the

system

path function



261 Throttling process is a reversible

and isothermal

process

an irreversible

and constant

entropy

262 A sample consisting of 1.00 mole of Argon gas is expanded

isothermally and reversibly at 0C from 22.4L to 44.8L. The heat

absorbed by the system is

0 +1.13 kJ

263 Maximum work can be obtained from a system when the change

taking place in it is

isothermal adiabatic

264 The ratio of work performed by a system and the heat it

absorbed from a reservoir is referred to

Entropy Gibb’s free

energy

265 According to the first law of thermodynamics Energy is

neither lost nor

gained in any

energy

transformation.

Perpetual

motion is

possible.

266 In a 3-stage compressor system whose isentropic efficiencies

are reported to be 0.75, 0.85 and 0.84, respectively, steam

initially at 10 kPa is compressed to a final pressure of 500 kPa.

The overall efficiency of the system is

greater than

0.85

in between 0.75

and 0.85

267 In choosing the refrigerant, the fluid must have the following

characteristics, except

environmentally

benign

has a vapor

pressure less

than

atmospheric

268 Coolers and boilers are ordinarily operated at ________

condition.

isobaric isenthalpic

269 For an isolated system, maximum entropy will occur at half-life critical condition

270 A carnot cycle consists of two isothermal

and two

adiabatic

process

two isochoric

and two

adiabatic

process

271 This is also known as the volume fraction of the voids in packed

beds.

sphericity porosity

272 A measure of the ratio of the drag force acting on a unit area of

the impeller & the inertial stress.

Froude number Reynold’s

number 273 Sulfuric acid is pumped at 3 kg/s through a 60-m length of

smooth 25 mm pipe. If the pressure drop falls by one-half, what

will be the new flow rate [kg/s]? Assume the following properties

of sulfuric acid: SG = 1.84, viscosity = 25 cP.

3 2



274 The equation del(P) = -(rho)(g) del(z) is known as the hydrostatic

vertical law for which all the following assumptions are applied,

except

shear forces

are not involved

fluid is

incompressible

275 Which of the following can be adjusted by human operator in a

closed feedback control loop?

set point controller output

276 The thermocouple is based on the Seebeck effect which states

that a/an _____ is generated when opposite junction of certain

dissimilar pairs of wires are exposed to different temperatures.

current temperature

277 Dead time is a function of distance and momentum acceleration

278 A pneumatic controller is used to control temperature within the

range 280K to 310K. The controller is adjusted so that the output

pressure goes from 20kPa (valve fully open) to 105 Kpa (valve

fully closed) as the measured temperature goes from 295K to

300K with the sent point held constant. What is the proportional

gain?

2.83kPa/K 0.35kPa/K

279 The parameter which completely describes the behavior of theresponse to a disturbance of a second order system is the Time constant dampingcoefficient

280 Water is flowing through a 3-inch schedule 40 pipe at 60 deg F.

A pitot tube is inserted at the centerline of the pipe and registers

a 3-inch Hg differential. What is the mass flow rate of the water?

11.61 ft/s 37.1 kg/s

281 An oil well is 1200 ft below ground level. Oil at 500 psig at the

bottom flows to ground level through a 12-inch schedule 80

commercial steel pipe. The oil has a SG of 0.86 and viscosity of

8 cP. The vol flow rate of oil in barrels per hour is

9365 9461

282 The equivalent diameter of a concentric annular space where 1-

inch OD pipe is located inside a 2-inch ID pipe is

pi/4 inch 1 inch

283 Based on Bond's crushing law, the power required to crush a

certain material will change by _____% if the diameter of the

product is made smaller by 50%.

20.2 41.4

284 The BPR of a 50% NaOH solution at an evaporator pressure of

4.7 psia is

73 degF 173 degF



C D ANSWER SCORE

globe valve orifice

a 1

0.03 0.038

0

turbulent flow

only

laminar flow

only 0

equal to the

heat transfer

coefficient

equivalent to

the resistance

offerred by the

pipe

equal to the

heat transfer

coefficient of

the steam d 1

the minimum

number of

stages occurwhen the tie

line coincides

with an

operating line.

the amount of

solvent used

must beenough to form

2 phases.

b 1

rectification fractionationc 1

minimum reflux optimum refluxc 1

mol/liter/min liter/mol/min

0

no effect significant

effect0

the heat

transfer is

constant

the

temperature is

uniform

throughout the

cylinder

0

transition plate bubble plate

0

supersaturated saturated c 1Sherwood,

Reynold's and

Schimdt No

Prandtl,

Schimdt and

Reynold's No

0

reduction ratio classification

ratio c 1



the value of k is

independent of

the initial

concentrations

of A and B

the reaction

cannot proceed

0

orifice venturi a 1

a function of

time

not uniform

throughout the

reactor and

varies from

time to time

0

book value market value

b 1

increases the

amount of

distillate

increases the

condenser duty0

the gas phase

resistance is

negligible

the ratio of gas

phase

resistance to

liquid

resistance is

approximately

zero

0

Peclet, Stanton

and Prandtl Nos

Schimdt,

Peclet and

Friction Nos

0

45-degree

standard elbow

square-corner

elbow 0

compressor accumulator

b 1

1" dia Drawn

tubing

4" dia Riveted

steel pipe 0

through each

material is

inversely

proportional to

the thickness of

the material

is constant

throughout the

series of

materials 0

parallel

reactions

consecutive

reactions c 1

air concretb 1

humidification extraction

b 1



tangential

pressure

static pressureb 1

concentration

gradient

momentum

gradient c 1

113 deg F 146 deg F

c 1

1.484 0.581 b 1

1.5 0.6

0

33.4 54.4

0

128 kg 32 kgc 1

26.4 57.8

0

1.5 2.75

0

over 20 million over 2 but less

than 3

0

0.0454 0.0252

0

6930000 2040000

0

saturation

temperature

dry-bulb

temperature 0

75.26 78.5

0



the temperature

of the air can

also be

maintained

constant

increase in the

humidity of the

air is

insignificant 0

0.02 0.01

0

equilibrium

moisture

content

critical

moisture

content

c 1

tray drier freeze drier c 1

air flow

perpendicular to

the surface of

the solid

air flow parallel

to the solid

surface

0

surface renewal moisture

diffusivity d 1

2.129 hrs 3.42 hrs

0

0.01155 0.00116

0

decreases with

time

no drying takes

place 0

to use cross

flow

evaporation

to use spray

percolators0

1.5 2.3

0



5 6

0

radiation all of A, B and

C a 1

radiation all of A, B and

C c 1

inverse of the

total resistance

sum of the

individual

resistances

c 1

evaporation all of A, B and

C b 1

451.7 475.1

0

5800 139200

0

5.51 m 4.14 m

0

966 kg 534 kg

0

85.8 sq.m. 88.5 sq.m.

0



14 kPa zero gauge

0

4.72 3.03

0

39 40

0

8 7

0

27.8 22.7

0

0.294 0.249

0

577 241

0



13.76 16.28

0

46.5 45.6

0

227.2 300

0

11994 20451

0

40130 45500

0

13.8 5

0

1163 19.4

0

4.67 2

0

95 100

0



7 0.52

0

31.7 37.1

0

851 900

0

0.75 1

0

[B]=0.4(1-

0.5 x )/(1- x )

[B]=0.2

0

25.2 20

0

3478 3750

0

0.714 6.01

0

100 25

0



13943 W 19343 W

0

23 33

0

38 0.038

0

both contain the

same no of air

molecules

0

increases by

about 40%

decreases.c 1

stays constant.c 1

stays the same. may increase

or decrease. a 1

The application

should be

rejected

because it

violates both

1st and 2nd

laws of Thermo.

The application

should be

given full

consideration

because it

does not

violate any

laws of

Thermodynami

cs.

0

increases 8x. increases 16x.

0

3 e7 5.2 e8

0



excess reactant product yieldb 1

reactant ratio fresh-feed

conversion b 1

Latent Heat of

Condensation

Net Calorific

Value 0

moisture volatile

combustible

matters

0

Ultimate

analysis

Elemental

analysis 0

O2-free basis N2-free basis0

Dulong's

formula

Oxygen

unaccounted

for equation

0

32.48 42.56 0

2.38 6.130

absolute

humidity of 0.05

60% saturation

0

PhP 434.16 PhP 450

0

0.03 0.05

0

4350 6000

0

9.5 17

0

0.9 0.92

0



51.2 22.76

0

7.86 23.1

0

1/conc 1/conc-time 0

2 1.50

adding a

catalyst

removing the

products of the

reaction

0

the net equation the rate law.

0

does not

depend on the

initial

concentrations

is not a

characteristic

of the reaction 0

8 160

nature of

reactants

temperature0

> 0 <0 0

log Ca vs

reciprocal time

1/Ca vs time0

lof Ca vs time Ca vs time

0

-ra = k Ca -ra = k Cb^2

0

Law of Mass

Action

Second Law of

Thermo 0

proportional to

initial conc

inversely

proportional to

initial conc

0

85.3 99.1

0

231 s 768 s0

19.1 min 10.4 min

0



8.33 9.33

0

52.63 m 56.23 m

0

0.3394 0.6197

0

300 527

0

0.327 0.237

0

12.7 20.7

0

9550 10150

0

Cao/(1-2m) Cao/2

0



37.1 31.8

0

1/32 1/64

0

2 40

2 40

2 40

the suction

pressure is toohigh

suction is lost

0

16.9 87.2

0

1.72 1.89

0

21 58.3

0

PhP 7000 PhP 12000

0

2 2exp2

0

velocity head dynamic head0

surface tension drag coefficient 0

63 85

0

4x3x6 3x2x130



248 320

0

8 10

0

77 94

0

25 30

0

there is a

vacuum

when the liquid

level is high0

efficiency none of thegiven choices 0

shell and tube extended

surfaces 0

0.89 0.92

0

17 m2

20 m2

0

255.65 214.65

0

less resistance

to heat flow

a porous

structure 0

accounts for

additional

resistance to

heat flow

none of these

0



Peclet number Prandlt number 0

heat transfer in

turbulent flow

heat transfer in

laminar flow 0

contaminated

coolingsurfaces

polished

surfaces 0

for fluids in

turbulent flow

when

Grashhoff

number is very

important

0

pressure-

vacuum

vacuum

0

0.76 0.65

0

1220 mm 2400 mm0

reduction ratio average

particle

diameter

0

0.7 0.6 0

sorting centrifugation

0

concentration electric field

0

concentration electric field 0

thermal and

ordinary

thermal and

Knudsen 0

J A = JB N A = -cD AB

dx A/dz 0

buffer region viscous sub-

layer 0

relative time relative position0

Bi Pe0

the interface either of the

bulk phases 0

in the liquid

phase

in either film0



water-cooling in

a cooling tower

heating of air

0

dehumidificatio

n and removal

of sensible heat

dehumidificatio

n by

condensing

water vapor ina refrigerator

0

adiabatic

saturation

temperature

dew point

temperature0

2 500

free moisture unbound

moisture 0

critical free

moisture

content

equilibrium

moisture

content

0

the solute

concentration of

the liquid and

gas phase are

equal

the solute

concentration

of the gas is

greater than

the liquid

0

1.77exp-6

1.22 exp-6

0

10050 11570

0

2.3 hr 2.9 hr

0

cm^3/sec cm^

2/sec^

2 0

50 1500

sieve-plate

column

wetted wall

column 0

remains

unchanged 0

vacuum

evaporator

falling film

evaporator 0

convective

mass transfer

all of these0



increase the

pressure drop

in the tower

reduce the flow

rate across the

column 0

the gas flow

rate is

maximum

the number of

stages is

infinite

0

0.51 0.68

0

0.71 0.65

0

20.9 22.4

0

0.87 min 1.18 min

0

equal to shear

rate of

deformation.

a linear

function of the

shear rate of

deformation.

d 1

incompressible incompressible

& inviscid d 1

1.84 0.25

0

streamline none of thesec 1

101.3 61

0

mean linear

velocity

local velocityd 1

venturi rotameter b 1

coefficient of

discharge

cross-sectional

area 0

velocity head static head c 1

< 5 0 0

Centrifugal

pump

Diaphragm

pump 0



34 ft 8 ft0

needle gate 0

resemble

closely to

isothermal

compression

are easy to

control0

1.5 5 b 1

fans compressorsd 1

viscosity surface tensiond 1

0.189 kg 0.198 kg

0

continuous

distillationwithout reflux

distillation

operating attotal reflux

0

less number of

trays

high reflux ratio0

an irreversible

phenomenon

always in

equilibrium c 1

both A and B either A or B

because these

two mean the

same thing

0

results due to

low gas velocity

is due to

bubble cups 0

feed phase and

solvent phase

overflow and

underflow 0

Absorption Strippingd 1

3-heptanol toluene

0

P.D. No. 232 P.D. No. 826 0

it depends not governed

by law 0

21 23

0

industrial

applicability

a technical

solution to

problem

0



request claims

0

Environmental

Impact

Assessment

Environmental

Critical Project 0

petroleum detergents 0

it poisons the

catalyst in the

refining process

all that are

mentioneda 1

builders perfume

c 1

copolymerizatio

n

naturalb 1

polymerization alkylationd 1

retarders fillers a 1

opacifier filler a 1

cellulose wastec 1

evaporation crystallizationc 1

bleaching calendering b 1

xylem lignin d 1

Dichlorodipheny

ldichlorobutane

diphenyldichlor

otriphenylbutan

e

c 1

oxidation purification b 1

thinner anti-skinning

agent a 1

increase

atmospheric

oxidation

give elasticity

and prevent

cracking of the

film

d 1

an inorganic

polymer

thermosetting

plastic c 1

vulcanization calenderingd 1

pesticide polyester a 1

polyester pigmentb 1

0.6784 0.7652

0

state function state

description of a

system

b 1



a reversible and

constant

entropy process

constant

enthalpy

process 0

+1.57 kJ +2.27 kJ

0

reversible irreversiblec 1

carnot

efficiency

Helmholtz free

energy c 1

Energy is

conserved in

quality but not

in quantity.

Energy is being

created as time

passes. We

have more

energy in the

universe now

than when time

began.

0

less than 0.75 in between

0.84 and 0.90

0

must be

economically

viable

exist at a high

pressure at the

condensation

temperature

0

isothermal isentropic

a 1

equilibrium start of the

process c 1

one isochoric,

one isobaric,

and two

adiabatic

process

one isothermal,

one isochoric

and two

adiabatic

process

0

superficial

velocity

specific volume0

Mach number Power number 0

0.2 0.124

0



z axis is defined

vertical &

downward in

direction

normal surface

forces & gravity

are the only

forces involved

0

process

variable

load variable0

emf resistance

0

time velocity d 1

17kPa/K 0.06kPa/K

0

Rise time overshootb 1

37.1 lb/s 317 lb/s

0

52581 393308

0

1.5 inch 2 inches0

50.5 58.6

0

233 degF 297 degF0



QUESTION A B

A valve that controls flow by means of a disk or wedge-shaped dam

sliding at right angles to the direction of flow and seating tightly in the

valve bod is a

gate valve butterfly valve

The friction factor for flow through a pipe with relative roughness of

0.004 at a Reynold's No. of 80,000 is approximately equal to

0.052 0.025

The equation that relates friction factor and Reynold's No.,

f=64/Reynold's No. holds for

smooth pipes laminar and

turbulent flow

Oil flows under laminar conditions inside a steam heated copper pipe.

The overall heat transfer coefficient is approximately

equal to the heat

transfer coefficient

of the oil

the average

between the heat


of the steam and

that of oil

In multi-stage liquid-liquid extraction with partially miscible solvents the extraction must

be done to form co-currently in order

to minimize the

extraction.

the minimum

number of stagesoccur when the

operating lines are

parallel.

The enrichment of the vapor steam as it passes through the column in

contact with the reflux during distillation is called

evaporation stripping

The maximum number of plates for a given distillation system is

obtained at

variable reflux maximum reflux

The correct unit for the specific rate constant for the reaction A--->B

determined to be first order is

square liter/square

mol/min

square liter/square

mol/square min

On one side of a heat exchanger where either a condensing vapor or aboiling liquid is present, the temperature may be assumed to be

constant. In determining the logarithmic mean temperature difference

the direction of flow will have

large effect little effect **ang kulit

ah! =P

For a cylinder where steady-state radial heat transfer takes place the heat flux is

constant

maximum heat

transfer rate occurs

at the surface **eh di

nga?

A plate holding a pool of liquid from which rises a vapor whose average

composition is in equilibrium with a liquid whose composition is the

average of that of the liquid leaving the plate is called

separation plate theoretical plate

Crystallization occurs in a solution that is concentrated

**concentration happens

when the amount of solvent

in a solution is decreased

unsaturated



Mass transfer in a flowing fluid may be correlated by Sherwood, Nusselt

and Reynold's No

Peclet, Reynold's

and Schimdt No

The ratio of the average diameter of the feed to the average diameter

of the product is the

settling ratio discharge ratio

The rate of formation of C for the reaction 2A + B ---> C is found to be

rate=k(A)(B) ***cguro w/c is true ang tanong? Hehe***

the rate of

formation of C is

equal to the rate of

disappearance of B

the order of reactio

is zero **how can u

say so?

A device for increasing the velocity of a fluid in steady flow is a nozzle vent **ang vent ay butas?

Di sisingaw? Babagal lalo

ang velocity, meh singaw eh.

In steady-state backmix flow reactor, composition is not constant

throughout the

reactor

constant

throughout the

reactor

The amount of money obtainable from the sale of used property over

and above any changers involved in removal and sale is called

net value salvage value

In fractionation, an increase in reflux ratio increases the

number of

theoretical lates

decreases the

reboiler duty

In mass transfer where the solute in the gas phase is very soluble in the

liquid phase ***cguro w/c is true ang tanong? Hehe***

the ratio of liquid

phase resistance to

the overall

resistance is close

to unit

the gas phase

resistance is

approximately equal

to the total

resistanceHeat transfer in turbulent flow may be described through an empirical

equation correlating

Nusselt, Stanton

and Reynold's Nos

Nusselt, Prandtl and

Reynold's Nos

Which of the following fittings exhibits the highest pressure drop for the

same flow conditions?

90-degree long

radius elbow

**K = 0.45

90-degree standard

elbow

**K = 0.75

A chamber into which steam from a high pressure line can be bled

during periods of low steam demand from the power plant is called

switching bank vent

Which one of the following pipes has the highest relative roughness? 2" diameter

Wrought iron pipe

4" dia Wrought iron

pipe

In steady-state heat transfer through a series of materials with varying

resistances, the heat transfer rate

decreases towards

the direction of

heat transfer

varies with the

thermal

conductivity of each

material

Reactions whereby reactants proceed along several paths and give

different products are

polymeric reactions reversible reactions



Which one among the following materials has the best insulating

property?

window glass wood

An operation where warm vapor mixture is cooled such as by contact

with a liquid resulting in condensation and decreased humidity is

evaporation dehumidification

The pressure exerted on a plane parallel to the direction of flow of a

moving fluid is called

gauge pressure velocity pressure

For mass transfer to take place, there must be a phase change reaction component

Water vapor condenses at 1 atm on a tube whose surface tmeperature

is at 80 deg F. in analyzing the heat transfer through the condensate

film, it is best to evaluate the liquid properties at

212 deg F 80 deg F

The diffusity of water in air at 100 deg F in sq.cm./sec is 0.256 0.278

A fluid flowing at a rate of 25 cubic meters per hour inside a 60 mm I.D.

i e has an avera e velocit in meter er sec e ual to

5.9 2.5

An equimolar mixture of benzene and toluene is subjected to a single

batch distillation. Distillation is discontinued when 60% of the benzene

in the feed is distilled. At this instance the bottom product when

analyzed shows benzene to be 36.4 mole%. In the distillate, the mole%

of benzene is

66.6 58.1

When 32 kg of methane is burned completely the theoretical oxygen

required is

16 kg 64 kg

The standard heat of reaction for the production of water gas, in

kcal/gmole, as given by the equation: C(s) + H2O(g) = CO(g) + H2(g) is

32.2 31.4

A rectangular duct 4 ft x 1.5 ft in cross section carries conditioned air. In

determining the pressure drop through the duct the equivalent

diameter in ft may be used which in this case is

4 2.18

A gas decomposition reaction has an activation energy of 245 kJ/mol.

The rate of reaction can be accelerated by using a platinum catalystwhere the activation energy for the resulting catalyzed reactions is

lower at 136 kJ/mol. Using Arrhenius' law and assuming the frequency

factor remains the same the catalyzed reaction is faster than the

original reaction by a factor of

over 100,000 but

less than a million

over 100 but less

than 200

Water at 100 deg F is flowing through a straight 4-in Sch 40 pipe at a

rate of 1.0 gal/min. The length of the pipe is 10 ft. The velocity at the

center of the i e in ft er sec is

0.0378 0.0504

A metallic rod 2 cm in diameter is used as a heating element. The

thermal conductivity is 370 J/sec.sq.m.degC. The surface temperature is

maintained at 200 deg C. For the center of the rod not to exceed 500

deg C, the maximum volumetric heat generation rate within themetallic rod in J sec cu.m. must be

4440000 5130000

This is a steady state temperature reached by a small amount of liquid

evaporating into a large amount of unsaturated vapor-gas mixture.

wet-bulb

temperature

dew point

Air, supplied at the rate of 1200 cfm to a refrigerated coil, has a relative

humidity of 20% and dry bulb temperature of 150 deg F. The mass flow

of dr air enterin er minute is

74.3 75



In adiabatic humidification, it is possible to maintain the temperature of

water constant since

according to the

phase rule, the

degrees of freedom

is 3

the system can be

well insulated from

the surroundings

An air-carbon tetrachloride vapor mixture at 100 deg F dry bulb and 60

deg F wet bulb is heated until the temperature reaches 180 deg F. thefinal ercent relative humidit is about

0.1 0.05

The portion of water in the wet solid that cannot be removed by the air

in its contact is called

free moisture final moisture

content

This type of drier is used for drying pasty materials such as wet filter

cakes and lumpy solids

rotary drier flash drier

In the constant-rate period, the rate of drying is established by a balance of the

heat requirements

for evaporation and

the rate at which

heat reaches the

surface

the internal

movement of

moisture beneath

the surface of the

solid

Unbound moisture in granular and porous solid moves through the

intertices of the solid by a mechanism involving

desorption surface tension

Wet solid is to be dried from 40% to 10% in 5 hours under constant

drying conditions. The critical moisture content is 20% and the

equilibrium moisture content is 7%. All moisture contents are on dry

basis. The time needed to dry from 15% to 5% free moisture under the

same dr in conditions is

0.542 hrs 1.846 hrs

If the rate of drying under constant drying conditions with air at 140

deg F and absolute humidity of 0.03 lb water per lb dry air of unknown

mass of solid is given by R=0.5-exp(-60X) [in lb water/hr-sqft], then the

equilibrium moisture content (db) of the material is

0.12 0.034

In drying at the falling rate period, the rate at which moisture is

removed from the solid material

remains constant increases with time

The major problem in diffusion is to promote diffusion of the solute out

of the solid and into the liquid. The most effective way of doing this is

to reduce the solid

to the smallest size

feasible

to use counter

current operation

A slurry flaked soybeans weighing 100 kg contains 75 kg inert solids and

25 kg of solution 10 weight % oil and 90% wt solvent hexane. This slurry

is contacted with 100 kg pure hexane in a single stage so that the value

of retention for the outlet underflow is 1.5 kg of insoluble solid per kg

solvent in the adhering solution. The composition of underflow leaving

the extraction stage in %wt oil is

0.3 0.8

Tung meal containing 55% oil is to be extracted at the rate of 4000 lb

per hour using n-hexane containing 5% oil as solvent. A countercurrent

mulitple stage extraction system is to be used. The meal retains 2 lb of

solvent per pound of oil free meal while the residual charge contain

0.11 lb oil per lb oil free meal while the product is conposed of 15% oil.

The theoretical number of ideal stages is

3 4



The movement of molecules over a substantial distance is associated

with the transfer of heat by


The mode of heat transfer that can take place in a vacuum is known as convection conduction

The overall conductance for a composite material in series is equal to

the

sum of the

individual

conductances

sum of the

individual

conductivitiesFilm and drop are terms associated with boiling condensation

A 6-in Sch 80 steel pipe is carrying glycerin at an average temperature of

100 deg F. The pipe is uninsulated, and the outside temperature is 30

deg F. The inside film conductance is 1000 Btu/h-ft-degF while the

outside film conductance is 3.0 Btu/h-sq.ft.-degF. Determine the heat

lost [Btu] per minute from a 75-ft length of the pipe. Glycerine is flowing

99.95 415.7

An oak (k=0.096 Btu/h-ft-degF) door, 30 in wide, 78 in high, and 2 in

thick, has 9 glass (k=0.45 Btu/h-ft-degF) windows, each 6 in by 8 in by

1/4 in thick. Determine the amount of heat lost [Btu] each day with a

surface-to-surface tem erature difference of 80 de F.

97 242

Determine the length needed for a simple concentric-tube, parallel flowheat exchanger to transfer heat from hot water to cold water at a rate

of 900 W. The heat exchanger consists of two Type K copper (k=386

W/m-degC) tubes. The smaller tube has an inside diameter of 49.8 mm

and an outside diameter of 54.0 mm. Assume that both film coefficients

are equal to 100 W/sq.m.-degC. The hot water enters at 90 degC and

leaves at 50 degC, and the cold water enters at 10 degC and leaves at 40

185.5 m 11.02 m

A saturated solution containing 1500 kg of potassium chloride at 360 K

is cooled in an open tank to 290K. If the specific gravity of the solution is

1.2, the solubility of potassium chloride per 100 parts of water is 53.55

at 360K and 34.5 at 290K, calculate the amount of crystals obtained

assuming that loss of water by evaporation is negligible.

4301 kg 1500 kg

An evaporator, working at atmospheric pressure, is to concentrate a

solution from 5% to 20% solids at the rate of 1.25 kg/s. The solution

which has a specific heat of 4.18 kJ/kg-K is fed to the evpaorator at 295K

and boils at 380K. Dry saturated steam at 240 kPa is fed to the calandria

and the condensate leaves at the temperature of the condensing steam.

If the heat transfer coefficient is 2.3 kW/sq.m-K, what is the required

area of heat transfer surface. The latent heat of vaporization maybe

taken as the same as that of water.

55.8 sq.m. 58.5 sq.m.



2.5 kg/s of a solution at 288K containing 10% dissolved solids is fed to a

forward-feed double effect evaporator operating at a pressure of 14

kPa in the last effect. If the product is to consist of a liquid containing

50% by weight of dissolved solids and dry saturated steam is fed to the

steam coils, what should be the pressure of the steam? The surface in

each effect is 50 sq.m. and the coefficients for heat transfer in the first

and second effects are 2.8 and 1.7 kW/sq.m.-K respectively. Assume

that the concentrated solution exhibits a boiling point rise of 5 degK,

that the latent heat has a constant value of 2260 kJ/kg and that the

specific heat of the liquid stream is constant at 3.75 kJ/kgK.

115 kPa 101.3 kPa

An acetone-air mixture containing 0.015 mol fraction of acetone has the

mol fraction reduced to 1% of this value by countercurrent absorption

with water in a packed tower. The gas flow-rate G is 1 kg/sq.m-s of air

and the water entering is 1.6 kg/sq.m-s. For this system, Henry's law

holds and Ye=1.75x, where Ye is the mol fraction of acetone in the

vapour in equilibrium with a mol fraction x in the liquid. How many

overall transfer units are required?

10.92 9.12

A still has a liquor composition of ortho-xylen 10%, meta-xylene 65%,

para-xylene 17%, benzene 4%, and ethylbenzene 4%. How many plates

at total reflux are required to give a product of 80% meta-xylene and

14% para-xylene? The data are given as mole percent.

37 38

A mixture of alcohol and water with 0.45 mol fraction of alcohol is to be

continuously distilled in a column so as to give a top product of 0.825

mol fraction alcohol and a liquor at the bottom with 0.05 mol fraction

alcohol. How many theoretical plates are required if the reflux ratio

10 9

Prepared cottonseed meats containing 35% extractable oil are fed to a

continuous countercurrent extractor of the intermittent drainage type

using hexane as solvent. The extractor consists of ten sections, the

section efficiency being 50%. The entrainment, assumed constant, is 1

kg solution/kg solids. What will be the oil concentration in the

outflowing solvent if the extractable oil content in the meats is to be

72.2 28.7

0.4 kg/s of dry seashore sand, containing 1% by weight of salt, is to be

washed with 0.4 kg/s of fresh water running countercurrent to the sand

through two classifiers in series. Assume that perfect mixing of the sand

and water occurs in each classifier and that the sand discharged from

each classifier contains one part of water for every two of sand (by

weight). If the washed sand is dried in a kiln drier, what percent of salt

0.492 0.429

Forty-five pounds per minute of water is heated from 60 to 180 deg F ina 5/8 in., 16 BWG heat exchanger tube. If the steam condensing at 260

deg F, on the outside of the tube gives an hо of 1000 Btu/hr-sq.ft.-degF,

calculate the inside heat transfer coefficient [Btu/hr-cu.ft-degF].

2173 696

How many cu.ft. per minute of entering air is needed to evaporate 10 lb

of water per hour from a rayon, if the air enters at 80 deg F and 25%

humidity and leaves at 170 deg F and 55% relative humidity. The

o eratin ressure is 14.3 sia.

12.54 12.68



Nicotine is to be extracted from water using kerosene. If 100 lb of a 2%

nicotene solution is extracted once with 200 lb of kerosene, what

percent of the nicotene is extracted? {Equilibrium data: Y[lb

nicotene/lb kerosene] = 0.90X [lb nicotene/lb water]}

64.5 54.6

We must cool 2500 gpm of water from 120 to 80 deg F. A cooling tower,

at 70 deg F and 1 atm, is to be designed to operate with entering air of

40% relative humidity. How many gpm of makeup water must be

supplied if windage loss is 95% of the amount lost by evaporation.

77.2 150

We wish to build an economical cold room 20 ft square and 10 ft high.

The outside temperature is 80 deg F and te room is to be maintained at

0 deg F. The boss has suggested parallel wooden outer and inner walls

separated by a 6-in air space. What will be the heat loss [Btu/hr]

throu h each wall?

3537 8457

A colloidal solution is to be concentrated from 15 to 65% solids. The

specific heat of the feed, entering at 50 deg F is 0.93. The pressure of

the saturated steam to the evaporator is 10 psia; the condenser

pressure is 5-in. Hg abs. The steam chest has an overall heat transfer

coefficient of 200 Btu/hr-sq.ft.-degF. Water must be evaporated at therate of 35,000 lb/hr. Neglecting boiling point elevation, what is the

10500 35000

What is the settling time [sec] for galena particles to settle under free

settling conditions through 5 ft of water at 50 deg F. Galena is spherical

in shape, with specific gravity and 0.01 inch in diameter.

38.1 18.3

A 10-ft diameter tank with a quick-opening value to a sump has a 10-ft

depth of liquid. How long [t in sec] does it take to drain the tank if the

valve is assumed to be equivalent to a 4-in diameter orifice? The liquid

densit is 60 lb cu.ft.

2951 1644

What size sharp-edged orifice [inches] was in use if a flow of 120 gpm

produced a 4-in Hg differential in a 4-in Schedule 40 pipe. The fluid,

measured at 60 degF, had a viscosity of 1 cSt and a specific gravity of 1.

2.21 1.35

Seven hundred gallons per minute of water are being discharged by a

centrifugal pump 5 ft above the pump inlet. The inlet pressure is 4-in Hg

above atmospheric and the discharge pressure is 29 psia. If the pump

has an 8-inch diameter inlet and a 4-inch diameter discharge, calculate

63 84

Determine the net positive suction head available to a centrifugal pump

when the level of water is just at the suction point. The pumped fluid is

water at 140 deg F and it is pumped from an atmospheric tank at 250

gpm. The tank suction point is 7 ft above the pump. The piping is 5-in

Schedule 40, 10-ft long with two short radius 90 deg elbows. [Use

density=61.38 lb/cuft, Pv=2.89 psi, viscosity=0.47 cP]

34.2 27.7

Water at 60 deg F flows through a 3-inch Schedule 40 pipe. A pitot tube

in the pipe shows a 3-inch Hg differential. If the pitot tube is located at

the center of the pipe, what is the mass flow rate of the water [lb/s]?

11.61 14.24



The gas phase irreversible reaction A+B---->C is elementary. The

entering flow rate of A is 10 mol/min and is equal molar in A and B. The

entering concentration of A is 0.4 mol/L. What CSTR volume [L] is

necessar to achieve 90% conversion?

113 227

The irreversible zero order gas phase dimerization 2A ----->A2 is carried

out in a packed bed reactor with 5 kg of catalyst. The entering pressure

is 10 atm and the exit pressure is 1 atm. Pure A enters at a flow rate of

10 mol/min. The reaction is zero order in A. What is the exit

conversion?

0.15 0.5

The gas phase reaction 2A+B----->C is carried out in a PFR. The feed is

equal molar in A and B and the entering temperature is 500K and the

entering pressure is 16.4 atm. If the exit conversion is x, then the exit

concentration of B is

[B]=0.4(1- x )/(1-

0.5 x )

[B]=0.4(1- x )/(1-

1.5 x )

Heat is generated in a 2.5 cm square copper rod at the rate of 35.3e6

W/cu.m. The rod is exposed to a convection environment at 20 deg C

where the convection heat transfer coefficient is 4 kW/sq.m.-degC.

Determine the surface temperature [deg C] of the rod.

75.2 55.2

A 5cm diameter cylinder is maintained at a constant temperature of 200deg C and it is "completely enclosed" by a wind tunnel test chamber,

walls of which are at 10 deg C. Air at 350K is forced across the cylinder

at a velocity of 50 m/s (h=180 W/m-degC). If the surface emissivity of

the cylinder is 0.7, determine the total (i.e., convective and radiative)

heat transfer from the cylinder [W per meter length].

13 272

A building wall consists of a 6- in of concrete (kc= 0.7 Btu/hr-ft-degF), 2

in of fiber insulating board, and 3/8 in of gypsum board (kg=0.03 Btu/hr-

ft-degF). The inside and outside heat transfer coefficients are 2 and 7

Btu/hr-sqft-degF, respectively. The inside temperature is 72 degF and

the outside temperature is 20 degF. Determine the overall heat

transfer coefficient for this wall [Btu/hr-sqft-degF].

0.028 0.119

Current is passed through a cylindrical laboratory heater, which has a 3

cm diameter, generating heat at the rate of 20 MW/cu.m. The heater is

exposed to a convection environment at 25 degC where the convection

heat transfer coefficient is 0.5 kW/sq.m.-degC. Determine its surface

tem erature de C .

325 300

A straight rectangular fin has a length of 3.5 cm, a thickness of 1.5 mm,

and is made of a material characterized by thermal conductivity of 255

W/m-degC. The fin is exposed to a convection environment at 20 degC

and h=1.5 kW/sq.m.-degC. Determine the maximum possible heat

transfer from this fin for the base temperature of 150 degC.

1500 W 4392 W

A gaseous fuel is composed of 20% methane( CH4), 40% ethane (C2H6)

and 40% propane (C3H8), where all percentages are by volume. The

volumetric analysis of the dry products of combustion (ie. everything

except the water) for this fuel gives 10.6% carbon dioxide (CO2), 3%

oxygen (O2), 1% carbon monoxide (CO) and 85.4% nitrogen (N2).

Determine the air fuel ratio on a mass basis for this reaction.

1 18



Dodecane (C12H26) gas at 25 degC is burned in a steady flow

combustion chamber with 20% excess air that enters at -23.15 degC.

The products leave the combustion chamber at 500K. Assuming steady

operating conditions and complete combustion, determine the required

mass flow rate of the dodecane to supply heat at a rate of 1.5 kW

170 100

Two rooms A and B of identical volume are connected by an opendoorway. The thermostat in the rooms are set so that Ta<Tb. Which

room contains more air molecules?

A B

If the absolute temperature of a gas is doubled, the mean speed of the

gas molecules

is doubled. increases 4 times

When ice cubes melt in a glass of water, the temperature of the

resulting mixture of water and ice

increases. decreases.

In all naturally occurring processes, the entropy of the universe increases. decreases.

An inventor seeking a patent claims that a building may be comfortably

heated in winter by a device that draws heat into the building from the

earth, even though the temperature of the earth is lower than the

desired temperature inside the building. He further claims that thequantity of heat supplied to the building in a given time period can

significantly exceed the work done by the device during the same

period. If you were a patent clerk (like the young Albert Einstein), what

should be your recommendation about the application?

The application

should be rejected

because it violates

the first law ofThermodynamics.

The application

should be rejected

because it violates

the second law ofThermodynamics.

A fixture containing an ordinary incandescent light bulb is connected to

a dimmer switch. The dimmer is adjusted so that the temperature of

the tungsten filament inside the bulb increases from 1300K to 2600K.

The total ower radiated b the bulb

doubles. quadruples.

A 30 MW geothermal electric power plant uses hot steam from the

earth at 157 deg C to heat and vaporize isobutane, which turns a

turbine that is connected to a generator. The isobutane is subsequentlycooled to 27 degC using fans and condensed back to a liquid. The

overall efficiency of the plant is 40% of the ideal (Carnot) efficiency.

How many joules of heat must be released to the atmosphere per

2.5 e8 2.2 e8

The material which remains unchanged in a process is limiting reactant tie substance

The ratio of the total quantity of a reactant present in the reactor feed

of a recycling operation to the quantity of the same reactant entering

the operation as fresh feed is the

recycle ratio combined feed ratio

The heating value measured when water formed from combustion is in

the liquid state.

Gross Calorific

Value

Heat of combustion

In the combustion of solid fuels, the tie element between the feed and

the refuse is the

cooked coal ash

The coal analysis which is based upon the volatilization characteristics

of the fuel is

Proximate analysis Modified analysis

An Orsat analysis of the flue gas when pyrite is roasted is on a SO2-free basis SO3-free basis

The empirical relation which allows one to compute for the net

hydrogen in a given solid fuel is the

Calderwood

equation

Theoretical Oxygen

Equation

The equivalent of 45degTw in the Baume scale is 26.63 28.32



A furnace completely burns coal containing 70%C. Analysis of the flue

gas shows 15% CO2, 4% O2, 81% N2, and no CO. What is the % of the

net h dro en in the coal?

1.2 1.53

Which has the lowest water content? dew point at

20degC

70% RH

A contract was made between a buyer and a paper manufacturer for

paper containing 5% moisture at PhP450/tonne FOB on specificationsthat price adjustment will be made if the quality is different. How much

should the buyer pay for 1 tonne of paper with 8% moisture content?

Freiht cost is PhP45 tonne.

PhP 405 PhP 424.26

One drier will dry a material from 45% moisture (wb) to 20% moisture

(db). From here the material enters another drier where the water

content is further reduced to give a final product weighing 1000 kg. If

the total evporation from both driers is 800 kg, the moisture of the final

roduct is

0.01 0.02

An experimental oil is used to distill 6000 kg.hr of Athabasta tar sand

which analyzes 30% 'heavy oil', 'light oil', and non-volatile matter. If the

distillate contains 12 % heavy oil and this constitutes 25% recovery of

the component, the weight in kg of the distillate obtained is

2250 3750

Coal fired in a furnace has a heating value of 13800 Btu/lb and contains

78.05%C and 1.2%S. The proximate analysis shows 4%M, 24%FC, 8%A

and the analysis of the refuse shows 8%VCM, 25%FC and 32% ash.

Calculate the % of C lost in the refuse.

4.22 8

Ninety grams of ethane and 384 grams of oxygen are fed continuously

to a laboratory furnace. The total combustion products collected was

16.2 gmole with no carbon dioxide. However, not all of the ethane was

burned due to faulty combustion. The fraction of ethane that was

0.8 0.85

The furnace at the Bataan refinery is using a fuel gas which contains

methane, ethane and 20% nitrogen. The orsat analysis of the

combustion products showed 7.8% CO2, 7.4% O2, and 84.8% N2. The

gas is burned with excess air. The % methane in the fuel gas is

63.25 57.24

Pyrite containing 78% FeS2 and 22% gangue is burned with excess air to

produce a stack gas with the following analysis: 7.29% SO2, 8.92%O2,

82.44%N2 and 1.35%SO3. If the cinder was found to have a partial

analysis of 62.10% Fe2O3, the % of FeS2 lost in the pyrite is

3.52 6.53

The unit of k for a 1st order elementary reaction is 1/time conc/time

If the temperature of a chemical reaction is raised by 10 degC, the rate

of reaction is increased by a factor of

4 3

The E of a reaction may be lowered by increasing

temperature

decreasing

temperature

The mechanism of a reaction can sometimes be deduced from the activation

energy

the temperature

dependency of the

rate



The equilibrium constant in a reversible chemical reaction at a given

temperature

depends on the

initial conc of the

reactants

depends on the

conc of one of the

products at

e uilibriumIf the volume of a reaction vessel is suddenly reduced to one half its

original volume the rate will increase by a factor of

2 4

The rate of reaction is not influenced by conc of thereactants

molecularity of thereaction

The net rate of reaction of an intermediate is 0 2

A reaction is known to be first order in A. A straight line will be obtained

by plotting

log Ca vs time Ca vs time

If the reaction 2A ---> B+C is second order, which of the following plots

will give a straight line?

Ca^2 vs time 1/Ca vs time

For the reaction A+B ---> 2C, when Ca is doubled the rate doubles, when

Cb is doubled the rate increases fourfold. The rate law is

-ra = k Ca^2 Cb^4 -ra = k Ca Cb^2

It states that the rate of a chemical reaction is proportional to the

activity of the reactants.

Le Chatelier's

principle

Hess' Law

The half life of a material undergoing second order decay is proportional to the

square of the initialconc

independent of

initial conc

A fluid flows through 2 CSTR in series. Each reactor has a capacity of

400,000 L and the fluid enters at 100 L per hr. The fluid undergoes a

first order decay with a half life of 24 hours. Find the conversion of the

fluid.

66.8 74.7

A first order reaction has a specific rate constant of 3e-3 per sec. The

half life is

0.0021 s 100 s

A certain reaction is 1st order in A. In 30 min, the concentration of A

decreases from 0.55 to 0.15 mol/L. The time it will take for A to

decrease from 0.35 to 0.15 mol L is

45.1 min 19.6 min

A gas decomposes at 900 degC according to 2A--->2R+S with a rate

constant of 1000 cc/gmol-s using pure A. The time it will take to react80% of A in a batch reactor at 900 degC and 1 atm in min is

3.83 7.43

Calculate the length of a chlorinating pipe line with diameter of 0.6 m

required to kill 95% of the bacteria in waste water flowing at 0.05

cu.m/s. Test shows that 95.33% kill is obtained in 5 minutes when

treated with 5 mg/L of chlorine. Chlorine disinfection kinetics is given by

the equation: dC/dt = k Ct^1.5 where C = number of bacteria. Assume

that the same concentration of chlorine is used in actual treatment

25.36 m 32.5 m

The set of data given below is for the parallel reaction: a---k1-->2R, a---

k2-->S. At t=0, Ca=15 moles/cuft, Cr = 1 mole/cuft, Cs=1 mole/cuft; At

t=1 hr, Cro = 9 moles/cuft, Cs = 3 moles/cuft. The value of K2 per hour is

0.1697 0.183



A batch reaction 2D+E----->F has a conversion factor expressed by the

equation r =0.24 t^0.5 where r = conversion factor based on the

reactant E; t = time in hours which ranges from 0.5 to 16 hours per

batch depending upon the process variables. The average molecular

weight of the feed is 60 and a density of 1.4 g/cc. The feed consists of 2

kgmole of D and 1 kgmole of E. The charging, cleaning and discharging

time per batch is 2.5 hrs and the volume of the reactor is twice the

volume of the feed. Assume 300 days per year and 12 hours

operation/day. The volume of the reactor in liters is

257 275

A container holds 100 gal of salt solution containing 50 lb of dissolved

salt. The bottom of the container is covered with a layer of rock salt.

The bottom of the container is covered with a layer of rock salt whose

surface is practically constant. The salt dissolved into the solution

according to r = k(C-3) where C is the concentration of the brine

expressed in lb/gal. If the water in the tank were fresh, the rate of

solution would be 1.0 lb/min. Fresh water enters at 3 gpm and brine

overflows at the same rate. Assume constant volume at any brine

concentration, the concentration of brine in container after 1 hour inlb/gal of salt is

0.732 0.427

An aqueous solution of ethyl acetate is to be saponified with NaOH. The

initial concentration of the ethyl acetate is 5 g/L and that of the caustic

soda is 0.10M. Values of the second order rate constant in L/gmole-min

are k = 23.5 at 0 degC; k = 92.4 at 20 degC. The reaction is essentially

irreversible. The time required to saponify 95% of the water at 40 deg C

10.3 11.4

At 500K the rate of bimolecular reaction is 10 times the rate at 400K.

Find E in cal, the activation energy for this reaction from Arrhenius Law.

8150 9150

The reaction A+2B--->R is 1st order with respect to each reactant. If

equimolar amounts of A and B are introduced into a constant-volume

reactor and (1/m) th of A remains after t1, how much will remain after

t2=2t1?

Cao/2m Cao/(2m-1)

When the 1st order homogeneous reaction (gas-phase) A--->2.5R is

carried out in an isothermal batch reactor at 2 atm with 20% inerts

present, the volume increases by 60% in 20 min. When the reaction is

carried out in a constant volume reactor, the time required for the

pressure to reach 8 atm if the initial pressure is 5 atm, 2 atm of which

consist of inerts in min is

43.1 41.3

When the ID of the pipe through which a fluid flows is doubled, the

pressure loss due to friction per unit length of pipe and for the same

volumetric flow rate is changed by approximately a factor of

1/8 1/16

When two centrifugal pumps are connected in series, the discharge

changes by a factor of

1/2 1

When two reciprocating pumps are connected in parallel, the

volumetric ca acit of the s stem chan es b a factor of

1/2 1

The pressure drop in a pipeline changes by a factor of _____ when the

velocity of the flowing fluid is doubled.

1/2 1



Cavitation occurs in a centrifugal pump when the discharge

pressure becomes

too hi h

the discharge valve

is closed

Oil with a viscosity of 30 cP and a density of 60 lb/cu.ft. flows through a

1/2-inch inside diameter pipe. Determine the velocity in fps below

which flow will be laminar.

0.63 13.1

Water at 60 deg F flows through a 3-inch inside diameter smoothhorizontal pipe. If the Reynold's number is 353000, calculate the ratio of

maximum velocit to avera e velocit .

1.05 1.22

The pressure after the pump in a 6-inch inside diameter smooth pipe

conducting water is 20 psia. The water is discharged at an open tank

100 ft from the pump. Calculate the rate of discharge of water in cu.ft/s.

0.6 3.58

A water storage tank assumes the supply of water into a factory. Water

is supplied to the tank through a booster pump installed in the water

line. The theoretical pump horsepower required is 3.25 hp. What is the

monthly operating cost of the pump if electric power cost on the

average is PhP 3.73/kWh. The pump is 65% efficient and operates for 12

PhP 3300 PhP 5000

When the impeller speed of an ideal centrifugal pump is doubled, the

vol. flow rate of discharge is increased by a factor of

1/2 1

The differential height between two points which a fluid has to be

transferred is the

potential head pressure head

The resistance of a layer of fluid to flow over the next layer is measured

by

viscosity friction factor

An axial flow pump operating at a speed of 880 rpm can supply water at

a rate of 3000 gpm. The maximum head that this pump can deliver in ft.

of water is

20 36

Specify the type of open impeller pump to use if the capacity is 400 gpm

at a head of 200 ft of water.

3x2x8.5E 4x3x8.5E

What will be the rated capacity [gpm] of a 4-1/2 inch impellercentrifugal pump operating at a speed of 3450 rpm capable of

eneratin a head of 40 ft of water.

95 134

If the speed of a centrifugal pump is doubled, the energy requirement

becomes approximately ___ times the original energy requirement.

2 4

A cylindrical tank 1 ft in diameter discharges through a nozzle

connected to the base. Find the time needed for the water level in the

tank to drop from 4 ft to 2 ft above the nozzle. The diameter of the

nozzle is 1 inch and its discharge coefficient maybe taken as unity.

32 55

The NPSH of a single suction centrifugal hot water pump at a speed of

3550 rpm operating at a pressure of 600 psi and a capacity of 450 gpm

is ___ ft.

15 20

The rate of evaporation at a given operating temperature in a n

evaporator is more when

when the operating

pressure is high

the operating

pressure is low

An optimim number of the effects for a given application is a function of

the

capacity economy

A popular type of heat exchanger for cooling large quantities of fluid is

the

double-pipe plate



An evaporator is used to concentrate 10,000 lb/hr of a 20% solution of

NaOH in water at 140oF using saturated steam at 25 psia at a rate of

7,000 lb/hr. The OHTC is 275 BTU/hr-ft2-oF when the pressure in the

vapor is 1.7 psia. The steam economy, SE, is

0.82 0.863

A cross flow heat exchanger uses mixed air at 4 kg/s that enters at 15oC

and leaves at 45

o

C. The air cools unmixed water, which enters at 95

o

Cand 0.70 kg/s. The OHTC equals 150 W/m

2-oC. After several months of

operation, a scale resistance of 0.002 m2-oC/W developed. 16. The heat

transfer area required to accomplish the change is

22.2 m2

25 m2

As solution of 28% wt Na2SO4 is to be crystallized to yield Glauber salt in

a four section (one section is 10 ft in length) Swenson Walker

Crystallizer. It is fed to the unit at 120oF and cooled to 60

oF using

cooling water which enters at 50oF and leaves at 70

oF. The crystallizer

has a cooling surface of 3 ft2 per foot of length. The feed rate is 500

lb/hr and the crystallizer is seeded with 50 lb/hr of 65 mesh crystals. 19.

The amount of the crystalline crop (C) produced in lb per hour is

285.3 249.3

An insulator should have low thermal

conductivity

high thermal

conductivity

Fouling factor is a dimensionless

quantity

does not provide a

safety factor for

design

Natural convection is characterized by Reynolds number Grashhoff number

The Graetz number is concerned with mass transfer

between a gas and

a liquid

absorption with

chemical reaction

Dropwise condensation occurs on clean and dirt free

surfaces

smooth clean

surfaces

Dietus-Boelter equation for determination of heat transfer co-efficient

is valid

for liquid metals for fluid in laminar

flow

A type of pneumatic conveyor system characterized by a material

movin in an air stream or ressure less than ambient.

fluidizing pressure

If the total percentage of particles larger than the screen opening in the

feed, oversize, undersize are 36%, 89% and 3%, respectively, the

effectiveness of the screen if the undersize is the product is

0.98 0.89

The estimated width of an apron conveyor having a capacity of 75

tons/hr at a speed of 50 ft/min is

305 mm 610 mm

It is defined as the ratio of the average diameter of the feed to theaverage diameter of the product.

settling ratio screen-mesh no

The sphericity of cubical particles is 1 0.87

The separation of a dilute slurry or suspension by gravity settling into a

clear fluid and a slurry or suspension by gravity settling into a clear fluid

and a slurr of hi her solids content is called

thickening classification



An imaginary line within a fluid flow such that a tangent at any point

indicates the direction of flow at that point.

stream tube velocity profile

Air at 250C [viscosity=0.018 cP] enters a section of 2-in schedule 40

commercial steel pipe at a gauge pressure of 310 kPa and a flow rate of

1200 kg/h. Assuming isothermal flow, what is the pressure drop [kPa]

in 60 m of i e?

350 155

A simple pitot tube measures acoustical velocity superficial velocity

Which of the following meters will have the highest permanent

pressure loss?

pitot tube orifice

In the flow meter equation, Y, indicates the mass flow rate compressibility

factor

The loss due to sudden contraction is proportional to velocity turbulence

Stoke’s law is valid when the particle Reynolds number is < 1 > 1

Priming needed in a Reciprocating

pump

Gear pump

Maximum theoretical suction lift for water at 60˚F by a centrifugal

pump is 34 ft. The same for water at 200˚F will be

40 ft 37 ft

The most economical valve for use with large diameter pipes. butterfly globe

Multistage compressors are used in industry because, they reduce the cost of

compressor

reduce the size

requirement

For ideally incompressible fluid, the mach number will be 0 1

of the following produces maximum pressure difference for

transportation of gases?

vacuum pumps blowers

The fluid property which matters for falling rain drops to acquire

spherical shape is its

pressure height of descend

A wastewater solution having a volume of 1000 L contains 0.21 kg

phenol/m3 of solution. A total of 1.40 kg fresh granular activated

carbon is added to the solution, which is then mixed thoroughly to

reach equilibrium. What is the amount of phenol absorbed per kg

carbon at e uilibrium?

0.007 kg 0.106 kg

The overhead product composition decreases with time in batch distillation

with reflux

continuous

distillation with

reflux

For a binary mixture with low relativity, continuous rectification to get

pure products will require

low reflux ratio small cross-section

Chemisorption is the same as van der

Waals

characterized by

adsorption of heat

The stage efficiency in leaching depends on the time of contact

between the solid

and the solution

rate of diffusion of

the solute through

the solid and into

the li uidWeeping in distillation or absorption column increases tray

efficiency

provides larger

surface for mass

transfer

What are the two contacting phase in leaching? extract phase and

raffinate phase

solvent phase and

solute phase

Hydrogen sulfide is removed from water by contacting the solution with

warm air. The operation is

Distillation Leaching



Disregarding the cost, which is the best solvent for the extraction of

acetic acid from an aqueous solution at 25deg C?

caproic acid chloroform

Professional Regulations Commission was created under P.D. No. 223 P.D. No. 233

A chemical engineer who designed and built a new type pf reactor and

for three years, sold many units to the public can still patent his reactor.

TRUE FALSE

A person who has passed the Chemical Licensure Examination can takehis/her oath as a chemical engineer if his/her age is not less than

_______ years.

18 19

Which of the following is not a requirement for utility model

registration?

inventive step novelty

A section of the patent application containing detailed descriptions of

the benefits obtained from using the invention is called the

disclosure abstract

A document issued by the DENR secretary indicating that the proposed

project will cause significant negative environmental impact.

Environmental

Impact Statement

Environmental

Compliance

CertificateIn the Philippines, sulfur for sulfuric acid manufacturing is sourced from

_______ industry.

paper cement

Sulfur is undesirable in petroleum because it causes engine

knocking

it increases the

boiling pt of fuel

Materials added to detergent formulation to enhance cleaning

performance by exhibiting synergistic cleaning effect with surfactant.

fillers brighteners

Polyethylene is an example of _____________ polymerization condensation addition

Principal chemical conversion in the production of resin from monomer. condensation hydration

Carbon black is added to rubber compounding as activator curing agent

The binder for all the powder materials of paint pigment vehicleA fibrous material left after cane sugar has been milled is commonly

called as

bagasse pulp

Molasses is a by product of raw sugar from the ______ process milling extraction

Kraft process is a common name for sulfate pulping sulfite pulping

Water insoluble cell binders of wood pulp cellulose

DDT means Diphenyldichlorotri

phenylethane

dichlorodiphenyldic

hloroethane

Rancidity of oil can be reduced by decoloration hydrogenation

Varnish does not contain pigment dryer

Plasticisers are added to paints to make it corrosion

resistant

make glossy surface

Silicone is thermoplastic a monomer

The process involved in converting rubber into a thin sheet or coating it

on fabric is called

extrusion mastication

Alkyl benzene sulfonate (ABS) is a detergent rubber

Neoprene is a monomer synthetic rubber



Steam enters an adiabatic turbine at 10 MPa and 500 deg

C at a rate of 3

kg/s and leaves at 0.1 MPa. If the power output of the turbine is 2 MW,

determine the turbine efficiency.

0.2348 0.3216

Work is a property of the

system

path function

Throttling process is a reversible and

isothermal process

an irreversible and

constant entropy

A sample consisting of 1.00 mole of Argon gas is expanded isothermally

and reversibly at 0°C from 22.4L to 44.8L. The heat absorbed by the

s stem is

0 +1.13 kJ

Maximum work can be obtained from a system when the change taking

place in it is

isothermal adiabatic

The ratio of work performed by a system and the heat it absorbed from

a reservoir is referred to

Entropy Gibb’s free energy

According to the first law of thermodynamics Energy is neither

lost nor gained in

any energy

transformation.

Perpetual motion is

possible.

In a 3-stage compressor system whose isentropic efficiencies are

reported to be 0.75, 0.85 and 0.84, respectively, steam initially at 10

kPa is compressed to a final pressure of 500 kPa. The overall efficiency

of the s stem is

greater than 0.85 in between 0.75 and

0.85

In choosing the refrigerant, the fluid must have the following

characteristics, except

environmentally

benign

has a vapor

pressure less than

atmospheric

Coolers and boilers are ordinarily operated at ________ condition. isobaric isenthalpic

For an isolated system, maximum entropy will occur at half-life critical condition

A carnot cycle consists of two isothermal and

two adiabatic

process

two isochoric and

two adiabatic

process

This is also known as the volume fraction of the voids in packed beds. sphericity porosity

A measure of the ratio of the drag force acting on a unit area of the

impeller & the inertial stress.

Froude number Reynold’s number

Sulfuric acid is pumped at 3 kg/s through a 60-m length of smooth 25

mm pipe. If the pressure drop falls by one-half, what will be the newflow rate [kg/s]? Assume the following properties of sulfuric acid: SG =

1.84 viscosit = 25 cP.

3 2

The equation del(P) = -(rho)(g) del(z) is known as the hydrostatic vertical

law for which all the following assumptions are applied, except

shear forces are not

involved

fluid is

incompressible

Which of the following can be adjusted by human operator in a closed

feedback control loop?

set point controller output



C D Comments!

globe valve orifice

a

! Un na nga ang gate valve. =P

0.03 0.038

E

! The correct answer is about 0.0095 from perry 8th fig 6.9 pge 6-

10 tingnan nyu pa

turbulent flow

only

laminar flow only

X

! Meron gang f=64/Re? baka f = 12/Re eto eh "Hagen-Poiseuille

Equation" for SMOOTH TUBES & LAMINAR FLOW from perry 8

same a e n nasa taas.equal to the heat


equivalent to the

resistance offerred

by the pipe

equal to the heat

transfer coefficient of

the steamd

xxx

the minimum

number of stagesoccur when the tie

line coincides with

an operating line.

the amount of solvent

used must be enoughto form 2 phases. b

xxx

rectification fractionationc

xxx

minimum reflux optimum refluxc

xxx

mol/liter/min liter/mol/min

E

! 1/time

k = (Volume(order -1)

) / (Concentration(order -1)

) x time

no effect significant effectc

! Eh constant nga ung temp nung isang stream..=P btw.. ∆Tlm =[∆T(side a) - ∆T(side b)] / ln [∆T(side a) / ∆T(side b)] a-----

--------------->b a--------------------->b a-----

---------------->b a<---------------------bthe heat transfer is

constant **panu pag iba na

ang heat transfer area?

the temperature is

uniform throughout

the cylinder **sinong

nanay mo?

a

! Steady State daw ang heat transfer… so steady o constant din

ang Heat Flux. Bakit hindi ung c? kasi di pwedeng sabihin na heat

transfer eh constant kasi ang heat transfer eh q lang.

Samantalang ang Heat Flux eh q/A.

***Amount of Heat Transfer = Heat Flux x Area of Heat Transfer ***

*** = ***

transition plate bubble plate

d

xxx

supersaturated saturated

c

! Sturated --> Solute = Solvent

Unsaturated --> Solute < Solvent

Supersaturated --> Solute > Solvent

**based on solubility***



Sherwood,

Reynold's and

Schimdt No

Prandtl, Schimdt and

Reynold's No c

! Look at p 5 - 63 to 5 -82 of perry 8th. Specifically, note the

dimensionless numbers being used at every MTC formula.

Nsh Nre Nsc

reduction ratio classification ratioc

! Malamang =P

the value of k is

independent of

the initial

concentrations of

A and B

the reaction cannot

proceed **isa ka pa^^

c

! Kelan ga naging dependent ang k sa initial concen ng kahit na

alin sa reaction? Sa Temperature lang dependent ang k**. Kaya

nga ang tawag sa k ay "specific rate constant" dahil specific sya

sa isang temp at sa isang reaction at sya ay constant! Hehe

**from Arrhenius eqn : lnk = - (E A / R) (1 / T) + lnk o

orifice **pabibilisin

nga, haharangan pa xD

venturi **meter? hehe

a

! Nozzle - ex. Pipe na papaliit ang diameter, papaliit din malamang

ang cross sectional area, at papabilis ang velocity ng fluid.

***flow of incompresible fluids***

mass flowrate = density x Area x velocity

a function of time not uniform

throughout the reactor

and varies from time to

time

b

! Bacmix Reactor is another name for CSTRs (Constantly Stirred

Tank Reactors) wherein ther is a constant composition

throughout which is assumed due to constant stirring.

book value market value

b

xxx

increases the

amount of

distillate

increases the

condenser duty ?

xxx

the gas phase

resistance is

negligible

the ratio of gas phase

resistance to liquid

resistance is

approximately zero

?

xxx

Peclet, Stanton

and Prandtl Nos

Schimdt, Peclet and

Friction Nos b

! Sila yung gamitin sa Heat Transfer by convection. See perry 8th

p 5.7, Heat transfer by conduction.

Nu Nre NPr

45-degree

standard elbow

**K = 0.35

square-corner elbow

**K = 1.3 d

! The higher the K (additional friction loss) the higher the

pressure drop. See page 6 -18 perry 8th.

compressor accumulator

1" dia Drawn

tubing

4" dia Riveted steel

pipe

through each

material is

inversely

proportional to

the thickness of

is constant throughout

the series of materials

parallel reactions consecutive reactions



air concretb

humidification extraction

b

tangential

pressure

static pressure

bconcentration

gradient

momentum gradientc

113 deg F 146 deg F

1.484 0.581 b

1.5 0.6

33.4 54.4

128 kg 32 kgc

26.4 57.8

1.5 2.75

over 20 million over 2 but less than 3

0.0454 0.0252

6930000 2040000

saturation

temperature

dry-bulb temperature

75.26 78.5



the temperature

of the air can also

be maintained

constant

increase in the

humidity of the air is

insignificant

0.02 0.01

equilibrium

moisture content

critical moisture

contentc

tray drier freeze drierc

air flow

perpendicular to

the surface of the

solid

air flow parallel to the

solid surface

surface renewal moisture diffusivityd

2.129 hrs 3.42 hrs

0.01155 0.00116

decreases with

time

no drying takes place

to use cross flow

evaporation

to use spray

percolators

1.5 2.3

5 6



radiation all of A, B and Ca

radiation all of A, B and Cc

inverse of the total

resistance

sum of the individual

resistances c

evaporation all of A, B and C b

451.7 475.1

5800 139200

5.51 m 4.14 m

966 kg 534 kg

85.8 sq.m. 88.5 sq.m.



14 kPa zero gauge

4.72 3.03

39 40

8 7

27.8 22.7

0.294 0.249

577 241

13.76 16.28



46.5 45.6

227.2 300

11994 20451

40130 45500

13.8 5

1163 19.4

4.67 2

95 100

7 0.52

31.7 37.1



38 0.038

both contain thesame no of air

molecules

increases by about

40%

decreases.

stays constant.c

stays the same. may increase or

decrease.a

The application

should be rejected

because it violates

both 1st and 2ndlaws of Thermo.

The application should

be given full

consideration because

it does not violate anylaws of

Thermodynamics.

increases 8x. increases 16x.

3 e7 5.2 e8

excess reactant product yield b

reactant ratio fresh-feed conversion

b

Latent Heat of

Condensation

Net Calorific Valuea

moisture volatile combustible

mattersb

Ultimate analysis Elemental analysis

O2-free basis N2-free basis b

Dulong's formula Oxygen unaccounted

for equation

32.48 42.56



2.38 6.13

absolute humidity

of 0.05

60% saturation

PhP 434.16 PhP 450

0.03 0.05

4350 6000

9.5 17

0.9 0.92

51.2 22.76

7.86 23.1

1/conc 1/conc-time a

2 1.5

adding a catalyst removing the products

of the reaction

the net equation the rate law.



does not depend

on the initial

concentrations

is not a characteristic

of the reactionc

8 16d

nature ofreactants

temperature

> 0 <0

log Ca vs reciprocal

time

1/Ca vs time

lof Ca vs time Ca vs time

-ra = k Ca -ra = k Cb^2

Law of Mass

Action

Second Law of Thermoc

proportional to

initial conc

inversely proportional

to initial conc

85.3 99.1

231 s 768 s

19.1 min 10.4 min

8.33 9.33

52.63 m 56.23 m

0.3394 0.6197



300 527

0.327 0.237

12.7 20.7

9550 10150

Cao/(1-2m) Cao/2

37.1 31.8

1/32 1/64

2 4

2 4

2 4



the suction

pressure is too

hi h

suction is lost

16.9 87.2

1.72 1.89

21 58.3

PhP 7000 PhP 12000

2 2exp2

velocity head dynamic head

surface tension drag coefficient

63 85

4x3x6 3x2x13

248 320

8 10

77 94

25 30

there is a vacuum when the liquid level is

high

efficiency none of the given

choices

shell and tube extended surfaces



0.89 0.92

17 m2

20 m2

255.65 214.65

less resistance to

heat flow

a porous structurea

accounts for

additional

resistance to heat

flow

none of these

Peclet number Prandlt number b

heat transfer in

turbulent flow

heat transfer in laminar

flow d

contaminated

coolin surfaces

polished surfaces

c

for fluids in

turbulent flow

when Grashhoff

number is very

important

pressure-vacuum vacuumd

0.76 0.65

1220 mm 2400 mm

reduction ratio average particlediameter

c

0.7 0.6 a

sorting centrifugation

a



concentration electric field

concentration electric field c

thermal and

ordinar

thermal and Knudsen

JA = JB NA = -cDAB dxA/dz

buffer region viscous sub-layer

relative time relative position

Bi Pe

the interface either of the bulk

phasesin the liquid phase in either film

water-cooling in a

cooling tower

heating of air

dehumidification

and removal of

sensible heat

dehumidification by

condensing water

vapor in a refrigerator

adiabatic

saturation

temperature

dew point temperature

2 50 b xxx

free moisture unbound moisturec

critical free

moisture content

equilibrium moisture

content

the solute

concentration of

the liquid and gas

phase are equal

the solute

concentration of the

gas is greater than the

liquid

1.77exp-6

1.22 exp-6

10050 11570



2.3 hr 2.9 hr

cm^3/sec cm^2/sec^2

50 150

sieve-plate column wetted wall column

remains

unchanged

vacuum

evaporator

falling film evaporator

convective mass

transfer

all of these

increase the

pressure drop inthe tower

reduce the flow rate

across the column

the gas flow rate is

maximum

the number of stages is

infinite

0.51 0.68

0.71 0.65

20.9 22.4

0.87 min 1.18 min

equal to shear rate

of deformation.

a linear function of the

shear rate of

deformation.d

incompressible incompressible &

inviscidd

1.84 0.25



3-heptanol toluene

P.D. No. 232 P.D. No. 826

it depends not governed by law

21 23

industrial

applicability

a technical solution to

problem

request claims

Environmental

Impact Assessment

Environmental Critical

Project

petroleum detergents

it poisons the

catalyst in the

refining process

all that are mentioned

a

builders perfume

c

copolymerization naturalb

polymerization alkylationd

retarders fillers a !

opacifier filler a !cellulose waste

c!

evaporation crystallization c

bleaching calendering b

xylem lignin d

Dichlorodiphenyldi

chlorobutane

diphenyldichlorotriphe

nylbutanec

oxidation purification b

thinner anti-skinning agent a

increase

atmospheric

oxidation

give elasticity and

prevent cracking of the

film

d

an inorganic

polymer

thermosetting plasticc

vulcanization calenderingd

pesticide polyester a

polyester pigment b



0.6784 0.7652

state function state description of a

systemb

a reversible and

constant entropy

rocess

constant enthalpy

process

+1.57 kJ +2.27 kJ

reversible irreversiblec

carnot efficiency Helmholtz free energyc

Energy is

conserved in

quality but not in

quantity.

Energy is being created

as time passes. We

have more energy in

the universe now than

when time began.

less than 0.75 in between 0.84 and

0.90

must be

economically

viable

exist at a high pressure

at the condensation

temperature

isothermal isentropica

equilibrium start of the process c

one isochoric, one

isobaric, and two

adiabatic process

one isothermal, one

isochoric and two

adiabatic process

superficial velocity specific volumeb

Mach number Power number

0.2 0.124

z axis is defined

vertical &

downward in

direction

normal surface forces

& gravity are the only

forces involved

process variable load variable



emf resistance

time velocity

17kPa/K 0.06kPa/K

Rise time overshootb

xxx

legend:

X = something wrong with the question

E = answer is not on the 4 choices

xxx = bakit ka a?if there is any revisions on answers, kindly inform me. Itama nyu

naman pag mali ako. Baka nagiimagine lang ako ng formula.Hehexxx

puro to kalokohan ha.. Hehe

! I found this thing on August 8, 09 and I started answering the

blank parts and correcting the wrong ones since then.

---------------------------------------------------------------bo a---la lang ̂ ^

ChE Reviewer

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