2016 Edgefield Sec Sci Chem Prelim

21 A student attempted to collect ammonia gas by using the experiment set-up.

stand andclamp

reagent- flask B

concentratedsulfuric acid

A bottom tubing of thistle funnel should be immersed in the reagent.

B bottom tubing of thistle funnel should be immersed in the reagent and calciunr

oxide should be used instead of concentrated sulfuric acid.

C gas collection by downward delivery should be done instead.

D two delivery tubes in conical flask B should be immersed in concentrated

sulfuric acid.

22 You are given a mixture of methylbenzene and aqueous solution of copper(ll)

sulfate. Methylbenzene boils at 111'C and is immiscible with water. Which two

methods could be used to obtain samples of methylbenzene and copper(ll) sulfale

crystals?

flrst method second method

A filtration crystallisation

B llltration evaporation

c using a separating funnel crystallisation

D using a separating funnet evaporalion

E DG/PRELll\1 EXAM.1 6/5C(CHEt'415076t507 8t1l4EXPlsN(A)ffS/AS104

What correction/corrections should be made in the apparatus set-up?

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23 A chromatography experiment is performed to determine the number of colouringspresent in a sample of food dye e.Chromatogram A shows the separation of colourings using methanol as the

solvent. The chromatogram is then removed, rotated clockwise by g0o and placed

in a second solvent, ethanol.

The results are shown in chromatogram B.

maaEclockrise

qP

--->sadng wtig qirinal

hcatinofQ

Chromatogram AChrornatogram B

How many different types of colourings are present in food dye e?

A3B5c6D8

24 The.table shows the structure of different atoms and ions.

E DG/pRELtM EXAM-1 6/SC(CHEMy 507 il5A7 8t1l4EXp/5N(A)rrS/AS

frs

Iir

fint

lirclccmdstrfiDg

Eus

a

a

a-v-

a

I

oa

ao

et

particleproton

numbernucleonnumber

number ofprotons

numhr ofneutrons

number ofelectrons

Mg

Mg'*

F

F-

12

X

II

24

24

19

19

12

12

II

W

12

10

12

'10

o

Z

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W X Y Z

A 10 10 I I

B 10 12 10 9

c 12 10 I 10

D 12 12 10 10

What are the values of W, X, Y andZ?

25 Propane burns completety in oxygen as shown in the equation'

CeHa (9) + 5oz (g) + 3COz + 4HzO (l)

lf 4.4gof propane is bumt completely, what volume of carbon dioxide is obtained'

measured at room temperature and pressure?

A 0.1 dm3

B 0.3 dm3

C 2.4 dm3

D 7.2dm3

26 20 cm3of ethyne, CzHz,are reacted with 500 cm3 of oxygen'

The equation for the reaction is

ZCzHz@) + SOz(9) -' 4COz(9) + 2H2O(l)

what is the totalvolume of gas remaining at the end of the reaction?

(allvolumes are measured at room temperature and pressure)

A 400 cms

B 450 cm3

C 490 cm3

D 520 cm3

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27 Element X forms an acidic, covalent oxide.

Which row shows how many electrons there could be in the outer shell of an atom

of X?

({ ) indicates presence and (x) indicates absence of number of vatence electrons.

number of valence electrons

1 2 6 7

A ./ { x x

B { x 't/ x

c x"l x {

D x x .l ./

28 The diagram shows the pH ranges of two indicators, methyl orange and methyl red.

methylorange red yellow

pH 23456

methl red red yellow

pH 23456

The table shows the pH of four solutions

ln which of the solutions are both indicators yellow?

A F only

B Y only

C Y andZ

D Zand E

E DG/PREL tM EXAM-1 6/SC{CHE My5076/5078/i /4EXp/5N(AyTS/AS147

solution Y z E F

pH 2.0 3.0 4.0 6.0

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29 Which of the following pairs of salts can be prepared using the same method?

A aluminium sulfate and ammonium sulfate

B barium sulfate and barium chloride

C calcium nitrate and copper(ll) chloride

D lead(ll) chloride and zinc sulfate

30 The diagram shows the structure of a covalent compound containing the element

hydrogen, H, and the unknown elements X, Y and Z.

/H x H

/Y-Z

H

To which groups of the Periodic Table do these three elements, X, Y and Z,

belong?

31 The following test tubes are set up to investigate the sacrificial protection of iron

EDG/PRELIM EXAM.l 6/SC{CHEMy5076/s078/1/4EXP/5N(A)rrS/AS108

YH

I

X

I

H

X Z

A IV It lil

B IV V1 V

C V t1 VI

D VI IV

--

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copper, magnesium or zinc piece is tied to the iron nailin each test tube.

nail nail nail

ln which test tubes will the iron nail rust?

A X only

B Y only

C XandZD Y andZ

32 Which one of the following ionic equations represents the reaction between bariumchloride solution and zinc sulfate solution?

A 2Ba.(aq) + SOa2-(aq) --- Ba2SOa(s)

B Ba2.(aq) + SOnz-(aq) --* BaSOa(s)

c Ba2.(aq)+ ZnSoe(aq)---+ BaSor(s) + 7nz"1uo,

D BaC/2(aq) + Znz*(aq) - ZnClz(ae) + Ba2.(aq)

33 Which equation shows an exothermic process?

A 2AgC(s) --+ 2Ag(s) + C/z(9)

B CaCO3(s) -, CaO(s) + COz(9)

C CHq(g) + 2Oz(9) -.* cOz(g) + 2HzO(9)

D HzO(| -- HzO(9)

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34 Which process involves a redox reaction?

A AgNO3 + HC, - AgC/ + HNO'

B CaO + ZHCI -- CaClz + HzO

C CuSOe + Zn -+ ZnSOa + 6p

D NaOH + HNOg --+ NaNOs + HzO

35 The diagrams show what happens when metals X, Y and Z are placed in water and

in dilute hydrochloric acid.

liquid metalX metalY metalZ

water

dilutehydrochloric

acidooo

What is the order of reactivity of the metals?

EDG/PREL|M EXAM-1 6/SC(CHEMy5076/s078i 1/4 EXP/sN(A)fiS/AS110

most reactive

-+

least reactive

A X Z

B X Z Y

c x Z

D Y Z X

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36 Hydrogen peroxide, Hzozwill decompose to produce oxygen and.water. 40 cm3 of0.4 mol/dm3hydrogen peroxide are used in this experiment, at a temperature of30"C. The results obtained are shown in curve e.

Volume of oxygen (cms)

-P

Trme tnnkrules)

Which one of the following witl produce curve Pgiven that the same volume ofhydrogen peroxide is used?

E DG/pRELIM EXAM-1 6/SC(CH EM)tsO7 6t507 AU4EXplsN(A)rrSlAS

concentration of H2O2 (mol/dm3) temperature ('C)

A 4.2 2A

B 0.2 40

c 0.8 20

D 0.8 40

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gas syringe

,esdion mhlure

For which two reactions would this apparatus be suitable?

reaction 1 : AgNOg(aq) + HCI(aq) -- AgCl(s) + HNOg(aq)

reaction 2 : 2HzOzGq) -, 2H2O(l) + Oz(g)

reaction 3 :MgO(s) + 2HCl(aq)'+ MgCl2(aq) + HzO(l)

reaction 4 : ZnCO3(s) + ZHCI(aq) -- Zn$lz(ag1 + COzG) + HeO(l)

A 1 and2

B 1and3C 2and4

D 3and4

38 The diagram shows the apparatus used for the fractional distillation of petroleum-

Which statement about the fractional distillation of petroleum is incorrecl?

A At each level in the column, only one compound is collected

B The higher up the column, the lower the temperature.

C The molecules collected at the bottom of the column are the least flammable.

D The molecules reaching the top of the column have the smallest relative

molecular mass.

cruda

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37 The apparatus shown can be used to measure thb volume of gas.given off.DAN

YAL

EDUCAT

ION

39 The diagram shows the structure of compound X.

H

H H

OH

Which statements about compound X are correct?

'1. Compound Xdecolourises aqueous bromine.

2. cornpound X turns acidified potassium manganate(vll) from purple tocolourless.

3. compound X reacts with sodium carbonate to produce a gas that gives awhite precipitate with limewater.

A land 2

B 1and3

G 2and3D All of the above

40 The structuralformula of a polymer is shown below

CII

IC}lo C#u

Which monomer will form this polymer?

B e

HI

CI

CI

EOG/pRE Lr M EXAM- 1 6/3C(CHEM)/5076/5078/1 /4EXP/5N(A)iTS/AS

H

IcI

OH

H

I(r-

9',)^---l-itH)

c,H. clI' " I

,lHH

DA

CI

?fr'I

c"l-1.l'"CI

H

HI

C_HIH

QttuI

'lCT

HI

CI

H

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1

SECTION A [45 marks]

Answer all the questions in the spaces provided.

The Dead Sea is a salt lake borderfng Jordan, Palestine and lsrael. lt is well knownfor its mineral-rich salt, with an overall salt concentration of 340 gil*r. ih" tablebelow shows th6 concentration of some of the ions present in the water of the DeadSea which has a pH between 5.9 and 6.0.

rons concentration in g/dms

chloride 121.4

bromide 84.3

magnesium 45.9

sodium 36.6

calcium 17.6

potassium 7.8

(a) Name the sart present in the rargest quantity in the Dead sea.

(b)

(c)

State the formula of an ion, other than those in the table, which rnust be presentin the Dead Sea.

Name the process by which the water from the Dead sea can be made intodrinking water.

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2 Milk of magnesia works as an antacid to treat stomach problerns. Milk of magnesia isa mixture of magnesium hydroxide and water. Tne sotulility of magnesium hidroxioein water is low.

Suggest how milk of magnesia works as an antacid.write a balanced chemicar equation to support your expranation.

t2)

? The diagrams show the electron arrangement in the outer shells of some atoms of theelernents from Period 3.

A EDD c D E

(a) (i) Define the term ,,isotopes,,

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of

sbmutant free

originsl

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4

(ii) Which of the above atoms are isotopes?

(b) What is the charge of the ion formed by element E? Explain.

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(c) (0 Write the formula of the compound formed between elements A and D.

(ii) Draw the 'dot and cross' diagram to show the bonding between elementsAand D. Only the outer shells of electrons need to be shown.

(iii) ls the boiling point of the compound formed between A and D high or low?Explain.

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4 To obtain fragrant oils used in perfumes, a method called stearn distillation is oftenused' The diagram below shows the apparatus used by a student to obtain fragrantoils from rose petals

rE0

.porous membrane

dtd Dot

(a) Explain why the upper container contains ice and cold water

(b) suggest what happens when steam passes through the rose petals.

(c) Two liquids would be collected in the receiving vessel.suggest and exprain a method to separate these two riquids.

hot|ralEI

t1l

11l

rrcefuhgTBssrl

12)

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b

5 Substance X is amixture of compound E and element F. Compound E is soluble inwater but element F is not soluble. The reaction scheme shows the results of someexperiments on substance X.

add water

warm dilutehydrochloric

dilute nitric acidand aqueousbarium nitrate

dilutesodiumhydroxide

acid

acidified sinitrate

ute ammoniasolutlon

solution

(a) ldentify substances E, F, P, Q and T.

(i) E

P

a

T

(b) Write an ionic equation, with state symbols, for the formation of white precipitate

T.

EDG/PRELTM EXAM-1 6/SC(CHEMy5076/s078/?4EXP/5N(A)nS

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(i i)

(ii.)

(iv)

(v)

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substanceX

grey residueF

solutioncolourleSS

colourless gasthat bums with

pop sound

whiteprecipitate, T

white precipitatesoluble in excess

aqueousammonia

yellowfiltrateE

whiteprecipitate,P

brownprecipitate, Q,

insoluble inexcess sodium

hydroxide

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6 The Periodic Table is an arrangement of elements in order of increasing atomicnumber.

Elements w, X, y and zare ail in the same period of the periodic Tabre.The following information about the erements is given.

. WzO exists as a strong basic oxide.o XCl3 is a covalent compound.o ! forms an ionic oxide yzOg.o I produces an ion Z -.

(a) Put W; X, Y and Z in their respective groups of rhe periodic Table on the basis ofthe above information.

W: Group

X: Group

Y Group

Z: Group

(b) Rubidiurn is in Group l. Suggest fuo physicat properties of rubidium that aredifferent from copper.

tzl

tzl

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7 A student investigates the reaction between magnesium metal and dilute acid Y. Thediagram shows the metal being added to the acid in a test tube, and also the sametest tube some time later.

magneslum50

20

't0

30

20

r0

acld Y--

magneslurn chloride soktbn

(a) What can you conclude from the diagram about the reaction between the metaland the acid? Give an observation to support your conclusion.

(b) The student further investigates the temperature changes when three metals, L,M and N are added to magnesium chloride solution.

O.2 g of each metal was added to a test tube containing magnesium chloridesolution and the maximum temperature of the mixture measured and recorded.

The table shows the results she obtained

metal initial temperature / oC maxirnum temperature / oC

L 29.5 29.s

M 28.5 33.5

N 30.0 34.0

The student concludes that the order of reactivity of the metals is as follows.

most reactiV€

->least

reactive

N M L magnesium

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Do the student's results agree with her conclusion? Explain your reasoning

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I The average concentration of carbon monoxide in the air in Orchard Road for two years isgiven in the table below.

tirne interval(hours)

6am-8 am 8 am -10 am 10 am -12pmyear 2001 2002 2001 2002 2001 2042

concentration ofcarbon monoxide(volume of carbon

monoxideper 1000 000cmJ of air)

2 3 4 5 1 2

(a) what is the main source of carbon monoxide at orchard Road?

(b) Describe the variation in concentration of carbon monoxide over the 6-hourperiod.Suggest an explanation for thjs phenomenon.

(c) Suggest a reason for the difference in concentration of carbon monoxide

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recorded over the two years.

I A solution of sodium hydroxide, NaOH, has a concentration of 2Og/dmg

(a) Calculate the concentration of the solution in mol/dm3.

(b) Sodiurn hydroxide reacts with ammonium sulfate as follows:

2NaOH + (NHa)2SOa + NdzSO+ + ZHzO + 2NHs

What mass of ammonium sulfate reacts with 300 cm3of 2.0mot/dm3sodium

hydroxide?

(c) Another aqueous sodium hydroxide solution is made by diluting 1.0 mole of

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sodium hydroxide to make up to S dmo of solution.What is the concentration of this solution in mol/dm3?

The table shows some information about a homotogous series of organic compoundscalledcycloalkanes.

name numbeiot carUon-atoms

full structural formula boiling point fC

cyclopropane q

HH\/C

Hr /' \. 1HH-lc-c'-H

-33.0

cyclobutane 4ll

H-C-C-HttH-C-C- Hlt

HH

12.5

cyclopentane5

FIH\/c

H. / \ ,HH -'c c(uttH-C-C-HttHH

40.2

t1l10

(a) Explain how the formulae in the table show that the organic compounds belongto the same homologous series.

(b) Put tick ({ in the boxes to show the statements about the cycloalkane

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homologous series that are true and (X) for the statements that are false.

(c) Draw the full structural formula of cyclohexane.

SECTION B [20 marks]

EDG/PRELTM EXAM"1 6/SC(CHEMys076/s078is/4ExPi5N(Ayrs

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121

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true false

They have the sarne percentage by mass of carbon.

They have the same empiricalformula.

They are unsaturated hydrocarbons.

They decolourise aqueous bromine in the presence ofsunlighL

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Answer any twoquestions on the writing paper.

11 A student investigates the reaction between 0,06 g of magnesium and excesshydrochloric acid with the apparatus shown below.

Mg (s) + 2HCt (aq)t MgCt2 (aq) + Hz (g)

|rydrogen

syringe

small testtube held bya piece ofcotlon

magnesiumhydrochloric acid

The student reads the volume of hydrogen in the syringe every minute. Theresults are shown in the table.

time in minutes 0 1 2 3 4 5 6 7

volume o[gasin cm" 0 23 35 45 52 58 60 60

gasgas

(a) Plot the volurne of gas against time on a piece of graph paper. Label this graphas GraphA,. l2l

(b) Explain why the volume of gas stays the same after six minutes. t1l

(c) Suggest the chemical formulae of the 3 ions found in the solution after sixminutes. t1l

(d) Suggest a change that can be made to increase the rate of reaction. Explainyour answer in terms of Collision Theory. I3l

(e) The student repeated the experiment using 0.03 g of magnesium.

EDGTPRELIM EXAM-1 6/SC(CHEMy5076/s078/3l4EXp/SNBlns

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(i) Calculate the volume of gas produced, leaving your answer in cm3. 12)

(,i) Draw, on the same axes as part (a), the shape'of the graph you wouldexpect for the experiment with 0.03 g of magnesium. Label his graph asGraphB, t11

12 (a) Below is a recipe that gives the steps for making blackcurrant wine:

Re,cip g" lglb lackcu rrant wi ne

1. Boil 4 dm3 of water and add 2 kg of sugar. Stir until all the sugardissolves.

2. Add 1.5 kg of crushed blackcurrants and let the mixture cool to 25 oC.

3. Add some yeast.4. Cover the container and leave it in warm place forfive days.5. Filter the mixture into a glass jar and fit an airlock.

(0 State one step in the recipe whichGANNOT be used to increase thespeed of reaction. t1l

(ii) Why was the mixture cooled before the yeast was added to it? t1l

(iii) Give the name of this process of making wine and give the structuralformula of the main compound made in this process. l2l

(iv) Write the equation for the formation of the rnain compound stated in a(iii). t1l

(v) What is the function of yeast in this reaction? t1l

(b) The blackcurrant wine may have a sour taste afler long storage,

(i) Give the name and chemical formula of the compound which causes thesour taste in blackcunant wine.

(ii) Suggest how the compound in (d)(i) might be formed.

(iii) Write the equation to show how the sour compound is formed.

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13 (a) Explain the following observations:

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(i) Greasing an iron nail prevents it from rusting. t1l

(ii) Acidic food can be safely packed in atuminium containers even thoughaluminium is a reac{ive metal. t1I

(iii) Ammonium nitrate and water are used in making a cold pack. t1l

(iv) Filarnent bulbs are filled with argon and not air. p)

(b) sodium hydride reacts with water as shown by the equation below.

NaH + HzO..* NaOH + l-1,

(i) Explain in terms of oxidation states, why this is a redox reaction. pl(iD State the reducing agent in the reaction.

t1l

(iii) state a reagent that can be used to identifu the reducing agent.What would you see when this reagent is added to the reducing agent? l2l

DATA SHEET

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PRELIM EXAM-2o16Sc(Chem)-P1Marking scheme

aNo.

21 22 23 24 25 26 27 28 29 30

Ans B G B D D C D A c B

aNo.

31 32 33 34 35 36 37 38 39 4A

Ans A B C C u C c A A D

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EDGEFIELD SECONDARY SCHOOL2OI 6 PRE LIMIN.ARY EXAITINATION

Sc(Chem istry)- s0t d SOT BtgSecondary 4 Express/S Normal (A)

Marking SchemeQ No. Answers

ONAS1 a

1bc

1

and neutralizes the acid in the stomach.+ o

Magn roxide is a baCe

+ 2HCl ) 1

1a(i) Atoms the same element the same rnumbebut different number of neutrons. 1

iA and Cb

loses 3 electrons to have stable octet ration

+3,1

1AD

1c(ii) CorrectA andD

diagram for"dot and

1

c{iii) HighcaBe aUSE lot of IS neededenergy to theovercome strong

electrostatic forces of attraction between opposite lytons.

1

1

4 a To condense1

h the rose petals, oilfrom theroseAs steam passes throug

1coiland water areas the immiscible

1

15 E : iron I

1

1P: barium sulfate 4

a 6I

T : silver chloride1b16 a W: Group I

X : Group VY: Group lllZ: vil

Every 2correctans 1

markb tumRubid has m IIp. e while

hhascopper umRubidiigh softtsm.p. and can be withcutscissora while becannot cut with a scissor

1

4I7 a Reaction

exothermthe acid is anbetwe en UMmagnesi

reactionas there is an increase in

1

1

1

laa

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b Displacement reaction is exothermic, the more heat given

off, the rnore reactive the metal. Hence, l-tl- is morereactive than M and both are more reactive thanmagnesium.When L is added to maqnesium chloride there is no hgatevgtVereactive than L:Thei6fore the oider of ieactivity shouldbe N>M>EagLe-sipm?L.Student's results do not aoree with her conclusion.

1

I

1

I lncornplete combustion of carbon fuels. I

b Concentration of carbon monoxide increases and thendrops and is highest between 8 and 10 am due to thelarge number of vehicles on the road during peak hour (8to 10 am).

1

1

c There is a higher concentration of carbon monoxide in

2002 compared to 2001 due to greater number ofvehicles on the road orvehicle ownership in2OAZ. 1

I a Concentration = 0.Smol/dm" 1

b 39.6 g Cal-1Ans-1

c 0.2 mol/dm' 1

10 a Hydrocarbon having the general formula CnHzn 1

b truetruefalsetrue

Every 2conect -1 mark

c Correct structura! formula of cyclohexane 1

a Correct axisCorrect plot

1

1

b Reaction has stopped 1

c Mgt*, H*, Cf ( all must be correct) 1

d lncrease in temperature or increase in concentration ofhydrochloric acid or use powdered magnesium.Explanation-e.g increase in temperature)increas.e.in kinetiq energv ofparticles)i ncrease in n uEber "of ,co llisjons2 i ncreasein q.u.mher of effegtlue collisions) increase in rate ofreaction

1

1

1

e(i) 30 cm3 Cal -1

Ans -1e(ii) Graph B.

o Steepness same as Graph A. Volume of gas is half ol llqph A

1

12 a(i) Step 5 1

a(ii) Yeast will die if the mixture is hot. 1

a(iii) FermentationStructural formula of ethanol

1

1

1

2

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a(iv) Co 1 2C2H5OH + ZCOz I

a(v) Yeast contains an that SU the reaction 1

b(i) Ethanoic acidCOOH

1

1

b(ii) Air oxidation 1

b(iii) + + + 1

13 a(i) Greasing forms a coating around iron and prevents it fromcoming into contact with air/orrygen and water which areneeded for

1

a(ii) Aluminium reacts with oxygen and forms a coating ofaluminium oxide around aluminum. This coating preventsacidic food from coming into contact with aluminium.

1

a(iii) When ammonium nitrate dissolves in water, heat isa bsorbed from th e suroundin g(en dothermi c reaction ) andtherefore used in a cold pack.

1

a(iv) When electricity passes through the tungsten ment inthe bulb, it converts to heat At high temperature tungstencan react with oxygen in airto form tungsten oxide whichcannot conduct electricity. At high temperature, tungstencannot react with argon which is a noble gas havingstable octet qqo[guration.

1

1

b(i) l+1 -1 +1 -2 +1 -2+1 0NaH+HzO+NaOH+Hz

Water is reduced as oxidation stateof hydrogendecreases from +1 to 0.Sodium hydride is oxidized as oxidation state of hydrogenincreases from -1 to +1-

1

.tI

b(ii) Reduci is sodium 1

b(iii) Acidified potassium permanganateChanges colour from pqplqlq colourless

1

1

3

rac

hydride

DANYA

L ED

UCATIO

N