Released Exam

III

Reaction coordinate

1. The activation energy for lhc forward, catalyzed reaction i

A. IT minus I

B. ill minus I

c. IV mio.u n D. IV minus ill

o caLalysL

Cataly~l

Incomplete combustion in motor vehicles may lead ro the formation of carbon monoxide gas, which is a hea lth hazard in high concentrations. Carbon monoxide gas is converted ro carbon dioxide gas in a catalytic converter before being emitted from the motor vehicle. This conversion is represented by the equation below.

2. The addition of a catalyst to the reaction represented by the equation above would i the ener~y transferred during the reaction and would ii the value of the equilibrium constant.

The statement above i. completed by the information in row

Row ' ii

A. increase increase '~

-

B. I increase not change

c. not change tnc rcasc

D. L_ not change not change -

Honey has a high concentration of fructose, C6H120 6(s). Fructo e has the same molecular formula as glucose but a different structura l formu la.

3. If 1.50 mmol o f fructo ·e is burned in a calorimeter that contain 250.0 g of water and the temperature increases by 3.85 °C, then the molar enthalpy of combustion of fructo e is

A. - 6.05 X I o-3 kJ/ mol

B. - 9.68 x 10-2 kJ/ mol

C. - 4.03 kJ/mol

D. -2.69 x J03 kl/mol

A technician performed an experiment to dclcnninc the molar enthalpy ofcombustion of prop:.me in a -.olderin£ Lorch. as represented in the diagram below.

·~---Tiu;rmom(;t~r F==;:=::III::Oit~-- Alumintum l"mer

·-+-It--- Water

...,...__ t'\lumintum calorimeter

Propane omlcierint~ lnrrh

4. If the cxpcrimem~l "alue of the mo]or cnth:tlpy of combustion of propane in the lechnician \,calorimetry experiment i ~igni ficantly different from the theoretical value. then the technician could reduce the discrepancy in Lhc data by

A. using a gla."' beaker to hold the water

.B. creating an enclm.ing shield ~round the apparatus

c. tah.ing the ~Liuminium calorimeter above the name

D. dccrca.-.ing. the mass of water in the aluminium calorimeter

Products

g c.

~ Rea~.:tunts

Reaction progress

6. The reartion represemecl in the dia}lrmn abm•e i. included as a term itz rile balam:ed elJlUIIion. i1 would be tl

T he statement above i. completed by the information i n row

Row , ;;

A. I exothermic reactant

B. exothermic product

c. endothermic reactant - -- --

D. endothermic product - - --

and if 1fze energy was ji

The bombardier beetle can release a chemical solution when threatened. G lands in the beetle produce hydrogen peroxide and hydroquinone, CJ14(0H)z(aq), which a re combined to produce the reaction represented by the overall equation bdow.

The equations listed below represent reactions that are related to the production of the chemical e lution.

Equations

I C6H4(0H)2(aq) ~ C6H40 2(aq) + H2(g)

0 H2(g) + 0 2(g) 7 H20 2(aq)

III H2(g) + ! 0 2(g) ~ H20 (g)

I\' H 20(g) 7 H20(1)

7. The enthalpy change for the overall equation is

A. +83.0 kJ

B. - 202.6 kJ

c. - 299.4 kJ

D. - 585.0 kJ

6 H = + 177.4 kJ

l:lH= - 191.2 kJ

6H = -24 1.H kJ

6H= - 43.8 kJ

The bombardier beetle can release a chemical solurion when threatened. Gland. in the beetle produce hydrogen peroxide and hydroquinone, C6H4(0Hh(aq), which are combined to produce the reaction represented by the overall equation below.

The equation. li ted below represent reaction. that are relaled to the production of the chemical solution.

Equations

I C6Hi0Hh(aq) ~ C6H40 2(aq) + H2(g)

II H2(g) + 0 2(g) ~ H20 2(aq)

III H2(g) + -102(g) ~ HiO(g)

IV H20(g) ~ H20(1)

t::.H = + 177.4 kJ

H = - 19 1.2 kJ

H = - 241.8 kJ

Ml = - 43.8 kJ

Use the following additional information ro answer the ne..xr question.

Eo= +0.70Y

8. Which of the following ubsrance would oxidize C6H4(0Hh(aq)?

A. Ag+(aq)

B. Cu2\aq)

c. Ag( ·)

D. Cu( )

Nitrogen can react with oxygen to form a variety of oxide. as represented by the following equations.

N2(g) + 02(g) + 182.6 kJ -7 2 O(g)

N2(g) + 2 0 2(g) + 66.4 kJ -7 2 N02(g)

2 N2(g) + 0 2(g) + 163.2 kJ -7 2 N20(g)

N2(g) + 2 0 2(g) + I 1.1 kJ -7 N20 4(g)

• The- oxidation numbe-r of nitrogen in

NO(g) is

N02(g) is

N20 (g) is

_____ (Record in the first column)

_____ (Record in the second column)

_____ (Record in the third column)

N20 4(g) is _____ (Record in the! fourth column)

Nitrogen can react with oxygen to fom1 a variety of oxides as represented by the following equations.

N2(g) + 0 2(g) + 182.6 kJ -7 2 NO(g)

N2(g) + 2 0 2(g) + 66.4 kJ -7 2 0 2(g)

2 N2(g) + 0 2(g) + 163.2 kJ -7 2 20 (g)

N2(g) + 2 0 2(g) + I 1.1 kJ -7 N20 4(g)

Use the following additional information to answer the next question.

1 NO(g)

2 N02(g)

3 N20(g)

4 N20 4(g)

:\ UllllTkal R l'spoltsl'

II The nitrogen oxides, hs red in order of increasing enthalpy of formation, arc _ .and __

The energy from a car banery is generated as repre ented by the equation below.

Pb( ) + Pb02(s) + 4 H +(aq) + 2 S04 2-(aq) ~ 2 PbS04(s) + 2 H20 (1)

6H = -315.9 kJ

9. If 15.0 g of Pb(s) reacts in a car bancry, the amount of energy released is

A. 4.74 MJ

B. 4.36 MJ

c. 22.9 kJ

D. 21.1 kJ

The energy from a car banery i. generated a. repre ented by the equation below.

Pb(s) + Pb02(s) + 4 H+(aq) + 2 S04 2-(aq) ~ 2 PbS04( ) + 2 H20 ( I)

6H = - 315.9 kJ

10. During the operation of a car battery, which of the following observations can be made?

A. The amount of Pb(s) increases as Pb02(s) is reduced.

B. The amount of Pb0 2(s) increases as Pb(s) is reduced.

C. The amount of Pb02(s) decreases as Pb(s) is oxidized.

D. The amount of Pb(s) decreases as Pb02(s) is oxidized.

The energy from a car battery is generated as represented by the equation below.

Pb(s) + Pb02(s) + 4 H+(aq) + 2 SO/ -(aq) ~ 2 PbS04(s) + 2 H20 (1)

AH = - 3 15.9 kJ

Use the following additional information to answer the next question.

Every car battery is given a CCA (cold c ranking amps) rating. A CCA rating of 600 means that the battery is capable of generating 600 A of current for a 30.0 s period at 0 °C.

11. Which of the following value. indicates how many coulombs a battery with a CCA rating of 600 produce during 30.0 of operation?

A. 20.0 C

B. 600 C

C. 1.80 X ) 0~ C

D. 1.74 X 109 c

I The electrolysis of aluminium oxide in an electrolytic cell occurs at high temperatures I so that the compound is molten.

12. Which of the following equations represents the reduction half-reaction when molren aluminium oxide undergoe electrolysis?

A. B. c. D.

A t3+(1) ~ Al(l) + 3 e­

A t3+(1) + 3 e- ~ Al(l)

2 o1- (l) ~ 0 2(g) + 4 e-

2 0 2 (I)+ 4 e ~ 0 2{g)

A student placed a large piece of zinc into a beaker of hydrochloric acid and collected all of the gas produced. Indicator were also added to monitor the change in pH.

18. Tf a student were to build a voltaic cell using solid zinc and hydrochloric acid, which of the following equipment would also be need ed?

A. An inert electrode for the cathode and a salt bridge

B. An inert electrode for the cathode and a power ource

C. An inert electrode for the anode and a salt bridge

D. An inert electrode for the anode and a power ource

Fireworks usually contain a mixture of explosives and orher chemicals. Some of rhe reactions that occur in a fireworks d isplay are repre. ented by the equations below.

I 4 A I(. ) + 3 0 2(g) ~ 2 Al20 3(s)

II KC104(s) ~ KCl(s) + 2 0 2(g)

III SrC03(g) ~ SrO(s) + C02(g)

TV 2 Mg(.) + 0 2(g) ~ 2 MgO(s)

V Fe30 4(s) ~ 3 Fe(s) + 2 0 2(g)

19. The equation above that represent a reaction in which the metal is being oxidized are

A. 1 and IV only

B. JJ and III only

c. I, lll. and rv D. 11 , Ill. and V

Ammonium nitrate, used to ma ke gunpowder and fi reworks, was extracted from animal manure in ancient China. During the explosion of gunpowder or fireworks, the ammonium nitrate reacts violently, as represented by the equation below.

Explosion of Ammonium Nitrate

20. During the explos ion of a mmonium nitrate, hydrogen

A. is oxidized

B. loses. e lectrons

C. is the oxidizing agem

D. has no change in oxidation number

-- Cd(s)

~-Porous (;Up

....,..--1-- LO moiJL Cd~(aq)

22. If the e lectrochemical cell in the diagram abo e produce a How of electrons in the direction indicated, then M(s) and M 2\ aq) could be

A. Fe(s) and Fe2+(aq)

B. Pb(s) and Pb2+(aq)

C. Ni(s) and Ni2+(aq)

D. Cu(. ) and Cu2+(aq) Feedback on Alternatives

Statements About Electrochemical Cells

I The reaction is spontaneous.

IT The reaction is nonspontancous.

Ill Anions migrate to the anode.

TV Cations migrate to the anode.

V Electrons are gained at the anode.

VI Electrons arc gained at the cathode.

23. The statements above that correctly describe an electrolytic cell are

A. I, lll, and V

B. I, IV, and VI

c. n, Ill, and VI

D. n, IV, and V

24. The tatement cell are

A. l and ill

B. ill andVT

c. IV and V

D. IV and V1

Statements About Electrochemical Cells

I The reaction is spontaneous.

n The reaction is nonspontaneous.

ill Anions mig rate to the anode.

IV Cation migrate to the anode.

V Electrons are gained at the anode.

VI Electron are gained at the cathode.

above that correctly de ·cribe both an e lectrolytic cell and a voltaic

Iron metal reacr wirh hydrochloric acid slowly. The equation for this reaction i

Fe{s) + 2 HCl(aq) --? FeC12(aq) + H2(g)

25. In this reaction, the reducing agent is

A. FcCJ2(aq)

B. HCI(aq)

c. H2(g)

D. Fe(s)

A tudent drew the structural diagram shown below.

26. The IUPAC name for tlze stmctural diagram the swdenr drew is/- t -2- ii

The tatement above i completed by rhe information in row

Row t II

A. methyl ethyl butane

B. methyl cthylcyclobutanc

c. ethy l methy l butane

D. ethyl methylcyclobutane

Organic Compounds

1 2-methylcyclobut-l -ene 4 5-methylhept-3-yne

2 I ,2-dibromohcxanc 5 cyclohcptanc

3 2,2-dimerhylpentane 6 peman-1-ol

II The or-ganic compound numbered above th:u

is an alkene is (Record in lhc first column)

is an alcohol is (Record in 1hc econd column)

contains a triple bond is (Record in 1hc thi rd column)

is cyclic and saturated is ----- (Record in lhc fourth column)

1

2

3

Organic Compounds

H I 90

H-C-C I ' IT 0 - H

H H I I C-C-H

I H

4 H

H - C - C C - Br I

H

H 0 H I II I

11 - C - C - 0 - C - 11 I I

H H

H 11 I I

H- C-C- 0 - H I I H H

Match four of the organic compounds numbered above with their c1a. sifications beJow.

A lkyne (Record in the first column)

Alcohol (Record in the second column)

Aromatic (Record in the third column)

Un aturaled hydrocarbon _____ (Record in the fourth column)

Reaction Equation

I II

Qo H H 0~ I

H- C + I

H- C- 0 - H I

C- 0 - C - H + H- 0 - H ' o - H H

/ I H H

Names and Terms

1 Methane 6 Ester

2 Methanol 7 Polymer

3 Ethanoate 8 Esterification

4 Methanoic acid 9 Polymerization

5 Methyl methanoate

• fatch a name or a term from the Ji~t above with each descriptor given below.

Name of reactant I

Name of product n Type o f reaction

Classification of product n

----- (Ret.:ord in I he: first l:Oiumn)

----- (Ret.:ord in lht: second column)

----- (Record in 1he third column)

----- (Record in lhe fourth column)

The following are structura l diagrams for four organic compounds wi th common .induslri:d uses.

l .3 H I (/0

rr c - c H ' o H

2 H 4

BrO tO or CH, o

u CH., = CJ! - C - C - 0 - Cll., - C ll

~ I • 3

CH3 Br - C - Br

I Br

Match each o f the structural diag rams above wi.lh i~s clas~ificalion hclow.

Armnatic

Carboxylic acid

Unsaturated and aliphatic

Halogenated hydrocarbon

_____ (Rc~ord in 1he first l·olumn)

_____ (Record in 1he second column)

_____ (Record in lhe third column)

_____ (Record in lhe fourth column)

Hexane and hcx-1-cnc arc both colourlc liquid . One method u ed to differentiate between hexane and hex-1-ene is to add a few drop of orange-coloured aqueous bromine to sample of each organic compound.

27. Hexane is _ __._ __ hydrocarbon, a11d lzex-1-ene is _ _ , L.., __ hydrocarbon.

The statement abo\'e is completed by the infom1ation in row

Row l u

A. a saturated a saturated

an un aturatcd

a saturated - -

D. an unsaturated an unsaturated

Hexane and hex-1-ene are both colourles liquids. One method used to differentiate between hexane and hex-1-ene i to add a few drop of orange-coloured aqueous bromine to samples of each organic compound.

28. When aqueous bromine is added to hexane and hex-1-ene in the presence of light, the hexane undergoes i reaction and the hex-1-ene undergoes ii reaction.

The . ratement above is completed by the information in row

Row i II

A. an addition a substi tution

B. an addition an addition

c. a sub titution a substitution

D. a substitution an addition

Carbon-Containing Compounds

1 CCI4(1) 5 CO(g)

2 Fe3C(s) 6 C3H8(g)

3 C2H2(g) 7 NaCN()

4 C2H50 ll(l) 8 MgC0 3(s)

:\umLTiral RL·spunsL'

II The compounds numbered above LhaL can be classilicd as organic arc . and __

(Record all four digits of your an wer in lowest -to-highest numerical order below.)

The concentration of aqueous sodium hypochlorite, NaOCl(aq), in laundry bleach can be determined by titrating a . ample of laundry bleach with an iodide solution, as represented by the equation below.

llfl If a :-.tudcnt u~c 4.25 mL of a 0.047 3 moiiL T (aq) sol.ution Lo titrate a I 00.00 mL sample of laundry bleach. then the concentration of Ocl-(aq) in the laundry bleach is mmoi/L.

The concentrat ion of aqueous sodium hypochlorite, NaOCI(aq), in laundry bleach can be determined by titrating a ample of laundry bleach with an iodide solution, as represented by the equation be low.

30. The Kb ofOCI (aq) is _.....:;..___ , and OCL (aq) is a weaker base than _ ......:.:;ii __

The smtemenr above is completed by the information in row

Row ' II r-- -- -- -

A. 2.5 x Jo-7 P043-(aq)

B. z.s x to-7 CH3c oo-(aq) - - - -

c. 4.0 X JO-S P043--(aq)

D. 4.0 X JO- S CH3coo-(aq)

Citric acid. H3C6H50 7(aq), is a weak, polyprotic acid that is found in fruit. . uch a. oranges and lemons. Citric acid reacts with water, ao; represented by the following Bn.~nsted-Lowry equation .

H3C6H50 7(aq) + H20(1) :o= H2C6H50 7-(aq) + H30+(aq)

H2C6H50 7 -(aq) + H20( I) :o= HC6H50 /-(aq) + H30 +(aq)

HC6H5o l-(aq) + H20(1) :o= C6H50 71-(aq) + H30 +(aq)

31. The amphiprotic ~pecies in the equations above are

A. H3CJ150 7(aq). HC6H5o l -(aq). and H20 (1)

B. H2C6H5o 7-(aq). HC6H5o l-(aq), and H20 (1)

C. H3C6H50 7(aq) and H2C6H50 7 - (aq)

D. HC6H5o /-(aq) and C6H5o /-(aq)

K3 = 7.4 x 10- 4

K3 = 1.7 X 10 5

Ka = 4.0 x 10-7

Citric acid, H3C6H50 7(aq), i a weak, polyprotic acid that is found in fru its uch as oranges and lemons. Citric acid reacts with water, a repre ented by the following Br~nsted-Lowry equations.

H3C6H50 7(aq) + H20(1) - H2C6H50 7 -(aq) + H30 +(aq) K3

= 7.4 x 10- 4 -H2C6H50 7 -(aq) + H20( I) - HC6H50 / -(aq) + H30 +(aq) K

3 = 1.7 X 10- 5 -

HC6H5o l -(aq) + H20 (1) ...... C6H50 / -(aq) + H30+(aq) Ka = 4.0 X 10-7 -32. Which of the following tatement about Ka and Kb value applie to the equation

above?

A. The Ka of H3C6H50 7(aq) is less than the Kb of HC6H5o /-(aq).

B. The Kb of HC6H5o l -Caq) i greater than the Kb of C6H5o / -(aq).

C. The Ka of H2C6H50 7 - (aq) is greater than the Kb of C6H5o /-(aq).

D. The Kb of H2C6H50 7-(aq) is greater than the Kb of HC6H5o l -Caq).

Lactic acid, HC3H50 3(aq), is produced in human muscle cells when not enough oxygen

i upplied to the mu cle during heavy phy ical acti ity. The equation below repre ents the Br~nsted-Lowry reaction of lactic acid and water.

33. W hich of the following rows identifies the Br~nstcd-Lowry acids and a conjugate acid- base pair in the equa tion above?

Row Br~nsted-Lowry Acids Conjugate Acid-Base Pair

A. HC3H50 3(aq) and C3H50 3 (aq) H20 ( I) and H 3o +(aq)

B. HC3H50 3(aq) and C3H50 3 (aq) C3H50 3 (aq) and H30 +(aq)

c. HC3H50 3(aq) and H30 \ aq) H20(l) and H30 +(aq)

D. HC3H50 3(aq) and H30 +(aq) C3H50 3 (aq ) and H30 +(aq)

Lactic acid, HC3H50 3{aq), is produced in human muscle cells when not enough oxygen i supplied to the muscle during heavy phy ical activity. The equation below repre ents

the Br0n ted- Lowry reaction of lactic acid and water.

Use the following additional information to answer the next question.

A I 00.0 mL sample of lactic acid has a pH of 3.38.

II The hydroxide ion concentration in Lhis sample· of Jac[ic acid, expressed in scientific notation, is a.b x 10- cd moi/L. The values of a, b, c, and d are ______ , and __

(Record all four digits of your answer below.)

34. If a 100.0 mL . ample of 0.167 moi/L unknown acid ha. a pH of 2.32 at 25.0 °C, then the Ka i.

A. 2.9 X J0- 2

B. 4.8 x 10- 3

c. 1.4 X J0- 4

D. 2.3 x to-5

A technician placed a n amount of the colourless gas d initrogen tetraoxide into a flask. He clo ed the fla k and allowed the reaction to reach equilibrium. The dinitrogen tetraoxide partially decomposed to form brown-coloured nitrogen dioxide ga . The data collected during the experiment were recorded below.

Initial Concentra tion (moi!L)

Final Concentra tion (mol/L)

N0 2(g)

0.000

0. 180

35. The balanced chemical equation and equilibrium constant for the partial decomposition of d inirrogcn tctraoxidc gas arc

A. 20 4(g) ~ N02(g) Kc = 0.295

B. N20 4(g) ~ 2 N02(g) Kc = 0.053 I

c. !Q2(g) ~ N20 4(g) Kc = 3.39

D. 2 N02(g) :¢ N20 4 (g) Kc = 18.8

When the y tern repre ented by the equation below i at equilibrium in a 2.00 L ftaskat 15.0°C, theftaskcontains 1.1 5 mmol ofH2(g), 2.13 mmol of12(g), and 3.74 mmol of HI(g).

Ill' At 15.0 °C, the equilibrium conslanl is. -----

(Record your th ree-digit answer below.)