Spm_trial_chem_09_p123_ans.pdf

JUIANGJOHOR2OO9 CHEMISTRY PAPER1 ANSWER QUESTION

ANSWER

1

c

2 3

A

QUESTION

4 5 6

A

B

26 27 28 29 30 31

I

D

32

A

33 34

I I

10 11

12 13 14

15 16 17 18 19

20 21 22 23 ?4

25

D B

D D B

c c

A A A A B A A

c D

B B

c

35 36

ANSWER A

B B

c

B A

B D B D

c

37 38 39

D

40 41

A

D

c c

42

D

43

A B A

44

45 46 47 48 49

50

B A

D D D

,l -J-

2OO9 JUTANG JOHOFi (SPM) MAtAVSilA PETAJARAN silJilr GHEMISTRV (MARKING PAPER 2] $GHEME

SectionA Question Explanation No. 1 (a) (i) Puremetal : SubstanceX Alloy (ii)

(iii)

(b) (i)

: Substance Y

Mark 1 1

- Puremetalhasatomsof thesamesize/ same typewhichare orderlyananged

1

-Alloyhasforeignatoms

1

Substance Y.

1

Theforeignatomsdisruptthe orderlyarrangement of the metalatomsand preventthelayersof metal atomsfromslidingovereachother.

1

Polymers are largemolecules madeup of identical repeating whicharejoined unitscalledmonomers togetherby covalentbonds.

I Mark

1

HH (ii)

(iii)

H-c-c-cl

1

Nameof monomer:chloroethene

1

To makedrainpipes/artificialleatherlwater-proof /bags//as insulatorfor electric clothes/shoes wiring

1

10

Explanation

Question No. 2(a) (i)

Mark

Melting

1

(ii)

Molecule

1

(b)

Theheatenergyabsorbedby the particlesis used betweenthe to overcomethe forcesof attraction / particles. molecules naphthalene

1

E Mark

1

.;;

!Q

't

(c)

Theparticlesmovefaster

1

{ t: 3

(d) (i)

X :el ec tron

Y :n u c le u s

1

(ii)

Electron

1

(e) (i)

W andX

1

(ii)

Hasdifferentnumberof neutronsbutsame nucleonnumber numberof protons// hasdifferent proton number butsame

1+1

10

Explanation

Mark

E Mark

Question No. 3 (a) (i) (ii)

Solution l// |

1

Numberof mole= 25x 0.01= 0.00025 1000 = 0.00025 t\2.5 x 10-amol

1

Numberof H* = 0.00025x 6.02x 1023 = 1.5 x 1020

(iii) (b) (i)

1

Universalindicator// pH paper tt pH meter.

1

Number of moleof NaOH= 25x 0.1 1000 = 0.0025mol

1

E

H C I +N a OH )N a C l

+HzO

Fromthe equation, 1 mol of NaOH reactwith 1 mol of HCI 0.0025mol of NaOHreactwith 0.0025mol of HClll No. of mole of HCf = 0.0025mol Volumeof HCI = 0.0025x 1000 0,1 = 25 cm3 Correct diagram of apparatussef-up. Correct label.

t Hydrochloric acid/ HCI

Sodiumhydroxide/ NaOH solution

.t

Explanation Question No. to chemical energy 4 (a \ Electrical | Na*,cl-,H",oH-

(b)

I

(c) (i) Oxygen ] (ii) theglowingwooden InserUPlace/PuVBring splinterintothetesttube. // Theglowingwoodensplinterwillrekindles glowing splinter. wooden up the Gaswilllight (lf otherstest of gas given,notaccepted)

Mark

I Mark

1 1 1 1 1

(d) (i)

gas Chlorine

1

(ii)

of chlorideions/Cl'is higher - Theconcentration discharged is - Chlorideions/ Cl- selectively

1 1

(iii)

z0l-) Cl2 + ls

1

(e)

Platinum

1

10

4

Explanation

Numberof carbonatomspermolecule

oC as unit, X axiswithnumberof carbon atompermoleculeas label. scale 2. Suitableandconsistent 3. Smoothlinewith6 pointstransferred correctly 1 . Y axiswithboilingpointas labeland

increases. Thesizeof alkanemolecules Theforcesof attractionbetweenalkane moleculesbecomesstronger. Moreenergyis neededto overcomethe strongerforcesof attractionbetween molecules. Liquid Correctstructural formuIae Conect namesof the fwo isomers HHHH

H -C

ll l l l l rl H H ;H

C

Butane/ n-Butane

a

H

I

H-

c-H 1

HIH

rt l

c

c_ H

ttl

HHH 2-methylpropane Question No. 6 (a)

Explanation

1

10

Mark

E Mark

Chlorinewater/ AcidifiedPotassium (Vll)solution Manganate / Acidified (Vl)solution. Potassium dichromate

1

Cookingoil hasno freemovingions/ is a covalentcompound I containmolecular only

1

greento brown

1

Oxidationreactionis a reactionwhereiron (ll) ionsreleaseone electronto becomeiron (lll) ions.l/ Oxidation is lossof electrons.

1

Sodiumhydroxide solution / potassium (ll) solution hexacyanoferat / potassium cyanidesolution.

1

Zincsulphate

1

(ii)

Zn+C uS Oc )ZnS O r + Cu

1

(iii)

+2to0

1

(b) (c) (i) (ii)

(iii)

(d) (i)

'(iv) (v)

No. of mole of CUSO+

25xo'2= o.oo5 1000

massof ZnSOr = 0.005x 160= 0.8g.

1 10 1

4 ,!

.7

SectionB

7 (a\ (i)

Mark fMark

Explanation

Question No.

- To allowtheoxygen/ airto enterthecrucible

1

of magnesium combustion - forthe complete

1

2

_l (ii)

fEGmentI I Mass(s)

I lMg = - 30.64 | 30.64 -28.24 I 132,24

of l2L I Number moles of I 124 latoms | lSimplestratiol lofmoles t

l= 1' 6

= 0.1 1

I 1.6 = 0.1 I 16 | 1 | |

-l

I | | I |

fEmFrGAi-I formula

,l

I

1l 1

5

I

(bxi) |-| heatins

I Similaritv|

t' I

2l

I

I betweena gas I anda solid

I

lformed

I I I I

I I I The massof the I solidincreases

I betweena gas I I anda solid -TI

lrvtediis I

IDifferencewithoxygengas

1 I 1

tormeo

I

I

I reactedwith I qas I I hvdrooen I Themassof the I I soliddecreases I

I 1

Max.4

(ii)

acid// or anydiluteacid Dilutehydrochloric

2

Zinc llor any reactivemetal 1 (iii)

2HCl + .Zn +

ZnClz + Hz

(iv)

2

Max.6

2

Total marks

20

Question No I (a) (i) (ii)

Explanation Lead(ll)chloride/l Silverchloride// Mercury chloride Chemicalsneeded:Lead(ll)nitrateand sodium chloridell any suitableanswer Name of reaction:precipitationreaction// double decompositionreaction BlackpowderX: Copper(ll)oxide BluesolutionY: Copper(ll)chloride Cation:Coppe(ll) ion // Cuz* Anion:Chlorideion// Cl-

(cXi) Numberof molesof lead(ll)ions,Pbz* = numberof molesof lead(ll)nitrate,Pb(NO3)2 \

= 1 .0 x 1000 = 0.005mol Numberof molesof chromate(Vl)ions,CrO+2= nurnberof molesof potassiumchromate(Vl), KzCrOa = 1 .0 *

\

1

l0i0

= 0.005mol

1

1 mol of chromate(Vl)ions,CrOa2-reacted completelywith 1 mol of lead(ll)ions,Pb2*.

1

The ionicequationfor the reactionis: Pb2* + Croa2------->

PbCro+

n

7:

ri ,; ': a::,

i

(iii)

formedincreases - The heightof precipitate for the first4 testtubesbecauseas the increases, volumeof potassium chromate(Vl) is formed morelead(ll)chromate(Vl) - The heightof precipitaieformedbecomes constantwhenall Pb2.havereacted completely. to yellow - colourless Presence ionsgivethe of chromate(Vl) yellowcolourto the solutionl/ Chromate(Vl) ionsin the first5 test tubesare all reacted// ionsare In the last3 testtubes,chromate(Vl) in excess -To ensurethe heightof precipitate representsthe amountof precipitateformed - becausediameterof thetesttubesare the same Total marks

1

1I

1 1 6 I 1

20

10

SectionC

Question No

Explanation

M ar k fMark

e (a)

C o mp ound Moleculeformed formedbetween betweenZ andY X a n dY (i)

(ii)

Typesof l o n i cb o n dis chemical formedbecause bonds X atomdonates electrons and Y atom receives electronsto achievestable electron arrangement // X is metaland Y is non-metal

Covalentbondis formedbecause Z andY atoms sharethe electronsto achievestable electron arrangement // Y andZ ar e nonmetal

2

2 Boiling pointand melting point

(b)

Highbecausea lot of energy neededto overcomethe strong electrostatic forcesbetween ions

4

Low because lessenergyis neededto overcomethe weakforcesof attraction between molecules 1 1

2-

x2*

Y2-

X atomwithan electron arranqement of 2.8.2

1

ll

donates2 valenceelectronsto achievethe 2.8. X2* stableoctetelectronarrangement, + 2eX" X ion is formed// of 2.6 Y atomwithan electronarrangement octet stable the achieve to accept2 electrons 2.8.Y2-ion is formed electronarrangemenj, Yzll Y + 2e- -> ions,X2*and Y2' are The oppositely-charged attractedto eachotherbYa strong force. electrostatic XY is formed An ioniccompound (c) 1. A crucibleis filledwithsolidP untilit is halffull' 2. Two carbonelectrodesare dippedin the solidP and connectedto the batteries. is recorded' 3. Switchis turnedon and observation it melts until heated 4. The solidP is then completely. is 5. The switchis turnedon againand observation recorded. 6. Steps1 to 5 are repeatedusingsolidQ to replacesolidP. 7. Observations: P doesnot lightup the bulbin bothsolidand moltenstates. Q lightsup the bulbin moltenstateonly.

1 1

10

// any suitableanswer P: naphthalene ll anysuitablean$ /er bromide fead(ll) Q:

12

Question No. 1 0( a )

Explanation CH+

2Az

Mar k

CO2 + ZHzO

I Mark

I

R MMo f me th a n eC, H += 12 + 4 = 16

A

I

',|6g of methanereleases898 kJ heat

Thus 1 g of methanereleases= 898x 1 116kJ g-1 = 5 6 . 1 2 5k J g -1 (Correct answer and unit\

(b)

D i a qr am10.1 Diaqr am10.2 Temperature Increase Decrease

TotalEnergy content

Heat

AandB/ Ra n d S / reactants products have havehigher higherenergy energy content than contentthan its reactants / (P a n d Q ) its products / (C andD) Released

Absorbed

1 1

4

2 2

2

6

13

(c)

Plottedqraph 1. correctaxis and labelled 2. all 4 points/valuestransferredcorrectly 3. straightlinegraph 4. Consistentscale

1 1 4

I

1

Heatof^combustion of alcohols(kJ mol-1)

Numberof carbon

from Heatof combustionincreases ethanol -+ propafiol'-- butan-l-ol// methanol---+ methanol,ethanol,propanol,butan-l-ol, Heatof combustionincreases because: / mole 1. Numberof carbonatompermolecule increasesfrom methanolto butanol. 2. Numberof hydrogenatomsper molecule/ moleincreases frommethanoltobutanol. 3. MorecarbondioxidelCO2andwaterlHzO moleculeare formed.

4. Morecovalentbondsareformedin the products.

1

5. Moreheatis givenout.

1

Totalmarks

6

20

END OF MARKINGSCHEME

14

-

:'

zCICIg JULANG JOHOR (SPM] s[J[tPETAJARAN MATAVSTA GHEMISTRV (MARKTNG PAPER 3) SGHEME

:

E :5:

= QuestionNo. 1 (a)

MARKilygScHEME @en g

Rubric = Able teresstethe inferencecorrectlE

Score

Samplganswer: The reactivity(of alkalimetalswithoxygen)increasefrom lithiumto potassium. //

{

Lithium,sodiumand potassium / alkalimetalsshowsimilar chemicalin theirreactionswith oxygen. Able to state the inference/ess correctly. Sampleanswer: The reactivityincrease// Z

All metalsburnsproducedwhitefume andwhitesolidl/ GoingdowngroupI the reactivity increase. Able to stateany idea of inference. Sampleanswer: Lithium,sodiumand potassiumshowdifferentreactivity//

A

I

Potassium. Sodium.lithium lncrease

No responseor wrongresponse

U

ij.

:1

ffi Eb)

.+ Rlubr€ AbtEJostate the three variablescorrectly: = .Lfvtetnod b manipulatevatbble. @ fne respondingvariable3. The controlledvariable. Sampleanswer: 1) metals (i) Use differenttypes of (alkali)i(group

Score

= -1 ';{i

r#

-l

-

lI

I I I

(ii) Reactivityof metalswith oxygen// of the reactionbetweenmetalsand Vigorousness oxygen. (iii) Oxygengas// size/ massof metal I

p,Oteto stateany one variablecorrectly.

1

Ru b ric 1 (c)

correctlybetweenthe Able tdstatethe relationship and therespondingvariable. mamp@tedvariab:le :

Sampleanswer: (Thelower/higher the positionof metalin)/(Goingdown/up) Group1, the morellessreactiveis the metalin reactionwith oxygen.// the positionof metalsin group1, the The lower/higher is the reactivity. lower/higher The metalwhichis lower/ upperin Group1 is more/less reactivein reactionwith oxygen./i the metalin Group1 the more/less The lower/higher reactivethe reactionwith oxygen. Abte to statefhe relationshipbetweenthe manipulated variableand the respondingvariable. Sampleanswer: Reactivityincreasesfor the reactionbetweenalkalimetals and oxygenwhengoingdownGroup1/ fromlithiumto potassium. // (Thelower/higher the positionof metalin)/(Goingdown/up) Group1, the more/lessreactive.// in Group1 is more/less The metalwhichis lower/upper reactive i/ the metalin Group1 the more/less The lower/higher reactivethe reaction.// The morereactivethe reaction,the lowerthe positionof the metalin Group1. Able to statethe idea of hypofhesis. SampleAnswer: Metalsin Group1 can reactwith oxygen.// Alkalimetalshavedifferentreactivity.

No responseor wrongresponse

:

QuestionNo.

Ableto giveth&perationaldqfrnitionaccuratelyby stating .':

-

alkalimetals vigorously/ more vigorous/ reactive with axygen more / highlyreactive

Sampleanswer: An alkalimetalthat reactsmorevigorouslywith oxygenis a morereactivemetal. Able to give the operationaldefinitioncorrectlyby stating any two of the informationabove. Sampleanswer: The metalthatreactsmorevigorouslywith oxygenis a more reactivemetal.// The alkalimetalthatreactsmorevigorouslyis a more reactivemetal.// the alkalimetals,the more/lessreactive The higher/lower metal. Able to give the operationaldefinitioncorrectlyby stating any one of the informationabove. Samoleanswer: Alkalimetalscan reactwith oxygen.// with oxygen. Metalscan reactvigorously

No responsear wrongresponse

QuestionNo.

1 (eXi)

Abteto statethe Positionof

frX in Group1 accurately.

Sampleanswer.

peiiooslolz AA; to make a predictionof the positionof metalX in Group 1 /ess accurately. Sampleanswer: Below/underpotassium/l Lowerthan potassium Abteto nake anypredictionof the positionof metalX in

Group1. Sampleanswer: ln group1 /l UpperthanLi/Na/Kll LowerthanLi/Na /Voresponsear wrongresponse

ilstionNoF = 1 (e)(ii)

: ffiibric E + Able to arrangethe metalsin ascending;s76", basedw

Ttheir reactivity.

;.

Score

.;=

-F

I Sampleanswer: I

I Lithium,Sodium,Potassium, X ll

II

Li, Na, K, X

to arrangeany three of the metalsin ascending IAble based on their reactivitv.

order

II

I Sampleanswer: X, Li, Na. K ll Na, Li. K, X ll

Li, K, Na,X i/ Na.K, Li,X ll

L

K, Li. Na.X ll Li, X, Na. K

Ableto arrangeany two of the metalsin ascending order based an their reactivityor arrange in descending order. Sampleanswer: X, K, Lj,Na. ll X, Li, Na, K // K, X, Na, Li ll X, Na. K, Li ll

K, X, Na, Li Na. K, Li ,X

1

X, K, Na, Li ll

/Voresponseor wrongresponse

U

Score

massofsodl @etweenthe the time takenfor themifalto burncompletelyin -

thehigherthe mass/ the biggerthe size the longerthe time taken burn comPletelY

Sampleanswer: The higherthe massof metals,the longerthe timetakento i/ burn completelY. The biggerthe sizeof metals,the longerthe timetakento burn completelY.

ffitionship

betweenfhemassof sodium

and the time takenfor the metalto burn completelyin oxygen gas. Sampleanswer: The higherthe massof metalsthe longerthe timetaken'// More massmoretimeto burncompletely//

ffiionship

betweenthe /nassof sodium

and the time takenfor the metal to burn completelyin oxygengas. Sampleanswer: Biggermass burnslonger.// The metalsneedslongertime // More massmoretimeto burn' No responseor wrongresponse

QuestionNdF 1 (g)

e-

E

pu5rlc

=

ffi-ie

Able to reeordallthe re@thgswith one decimalplace

accgrately.

+ -F

Sampleanswer: 10.1, 10.6, 10.9 Ableto reeordany two readingswith one decimalplace accurately.

2

Sampleanswer: 10.8 ll 1 0 . 1, 1 0 . 5 ,1 0 . 9 ll 10.1,10.6,

1 0 . 0 ,1 0 . 6 , = 1 0 . 9

Abte to record at leastone readingwith one decimal place accurately. Sampleanswer:

1

10.1ll 10.6 ll 10.9 No responseor wrongresponse

0

QuestionNo. 1 (h)

bric

ffi

fq blue and red litmuspapel

-+

'correetly. Sampleanswer: Solutions GasJar I GasJar ll GasJar lll

Red litmuspaper Turnsblu e

Turnsblue Turnsblue

Bluelitmuspaoer No c h a n q e No chanoe No chanqe

Able to stateany one of the litmuspaper observations correctly. Sampleanswer: Solutions GasJar I GasJar ll GasJar lll

Red litmuspaper

Turnsblue Turnsblue Turnsblue

tl Red litmuspaper Solutions Turnsred GasJar I Turnsred GasJar ll Turnsred Gas Jar lll

Bluelitmuspaper

Turnsred Turnsred Turnsred Bluelitmuspaper No chanoe No c h a n q e No c h a n o e

Able to give an idea on litmuspaperobservations. Sampleanswer: Solutions Gas Jar I GasJar ll GasJar lll

Redlitmuspaper No chanqe No chanqe No chanqe

No responseor wrongresponse

Bluelitmuspaper

Turnsblue Turnsblue Turnsblue

=:

QuestiffiNo. /i \ -

Score

Rubri€

the Abteto write the two balancedcheffical equation-,4.or reaction accurately.:= € Sampleanswer * Oz

)

2NazO

ii. NazO + H2O )

2 Na O H

i. 4Na

and

withanyalkalimetalsfrom Notes:Sodiumcan be replaced Table1. Able tc write two chem'rcalequationswith correct chemical formulaehut not balanced// Any one of the two balanced chemicalequationsfor the reactionaccurately. Sampleanswer: +

)

02

i.

Na

ii.

NazO + HzO )

i.

4Na

ii.

+ 02

)

Na2O + H2O )

Na2O and NaOH

ll

2NazO

ll

z

2NaOH

Able to give at least one chemical formulaeof the subsfancescorrect// Ableto write any ane oi the two chemicalequationswith correctchemicalformulaebut not balanced. Samoleanswer: ll

NazO

ii. Na2O

HrO ll

NaOH

i. Na

Oz )

NazO

ii. Na20

Hzo )

NaOH

Na

v2

Noresponseor wrongresponse

and

1

ll

0

10

QuestionNo. r/:\ r u.l := .€

intostrong Abteto ciasslfuall alkalinesoluflons : one weak alkalicorrecfF Sampleanswer: / NaOH' Strongalkali. Sodiumhydroxide I KOH hYdroxide Potassium Ca(OH), / CalciumhYdroxide NH3 Weakalkali : Ammoniasolution, @rong correctly.

atkaliand one weak alkali

T

Sampleanswer: / NaOH, Strongalkali: Sodiumhydroxide i KOH PotassiumhYdroxide Weakalkali : Ammoniasolution/ NH. @ correctly.

of strongalkaliandweakalkali

Sampleanswer: Strongalkali: SodiumhydroxideI NaOH// PotassiumhYdroxideIKOH ll CalciumhYdroxideI Ca(OH)2ll Weakalkali : Ammoniasolution/ NHe No responseor wrongresponse

11

€ -a--::

:

:€

;!r

€: ExperimeE{' *"rtrO.T H2SO4) -:=

Questj:e$No. =

2 {i,\

:

:::

::

Na2SOa+ S +EOz

.r r n <+

+ l-12Lr:-

a

;+*

Rubric

:

Score

Ableto give the sffiment of the problemaccurately. Responseis in quesflonform. Sampleanswer: Doesthe temperatureof sodiumthiosulphate solutionaffect the rate of reaction? ll Howdoesthe temperature of sodiumthiosulphate solution affectthe rateof reaction?// Howdoesthe high/ low tefiperatureof sodiumthiosulphate solutionaffectthe rateof reaction? Responsein questionform. Sampleanswer:. Doesthe increase/ decreasein temoerature increase/decrease the rate of reaction?//

z

affectthe Howdoes the increase/decrease in temoerature rateof reaction? Able to give an idea of statementof the problem. Sampleanswer: Doestemperatureaffectthe rate of reaction? in temperature will increase The increase/decrease /decreasethe rate of reaction.//

I

will increase/decreasethe The higher/ lowerin temperature rateof reaciion.// To investigate the effectof temperature to the rate of reaction.

0

QuestionNo. 2 (ii; :

y'"

Rubric

gcore

the thre€v ariables correctlY

Sampleanswer variable: Manipulated solution of sodiumthiosulphate Temperature Rate of reactionl/ Timetakenfor mark 'X' to become /disappear invisible Constantvariable: sulphuric of sodiumthiosulphate/ Volumeand concentration acid / sizeof conicalflask Abte to stateany two variablescorrectly Ableto stateany one vaiables correctly No responseor wrongresponse

2 1

n

l:

';:

13

Qtfttion No.

? (iri) '=--*

.:: -= RE*Fric Able to s/afe fhe relationship;&rrectlybetweiZpthe manipulatedvaliableandthe respondingvafrble with directian. ;$.

Score

Sampleanswer: The higher/lower the temperature of sodiumthiosulphate solution,the higher/lower the rate of reaction./l The higher/lower the temperature of sodiumthiosulphate solution,the shorter/longer the timetakenfor mark'X' to disappearfrom sighVview // The increase/decrease in temperature of sodium thiosulphate solultonwill increase/decrease the rateof reaction.// Whenthe temperatureof sodiumthiosulphate solution increaseidecrease,the rateof reactionwill increase/decrease. Able to statethe relationshipbetween the maniputated variable and the respondingvariablewith direction. Sampleanswer: The higher/lower the temperature, the higher/lower the rate of reaction.// z

The higher/lower the temperature, the shorter/longer the timetakenfor mark'X'to disappear ll The !ncreases/decreases in temperature willincrease /decreasethe rateof reaction.// Able to statethe idea of hypofhesis. Sampleanswer; Differenttemperature, differentreactivity. //

1

Temperaturechanges,the time takenis different.

No responsearwrongresponse

tl

14

QuestTonNo.

2@i --:::-

Rub& Ableto givecompbte tistof m Sample answer:

Score

F

Materials: Sodium thiosulphate solution, sulphuric acid. Apparatus: Conicalflask, burner, measuring cylinder (10ml),, ,bunsen measuring (50ml),stop-watch, cylinder filter/white /cardboard paper.

3

Able to give completelistof mateials ana four apparatusas following. Answer: Materials: Sodiumthiosulphate solution, sulphuric acid.

2

Apparatus: Conicalflask,thermometer, bunsenburner,filterI white icardboardpaper. Able to give at leastone subsfancesand at leastone apparatus.

No responseorwrong response

I

n

15

:

Qu€stionNo. €

2 (v) :::..

-:l

Rubric Ableto listallJhe steps correctly -

-=

-E

ScoiE -J.

I

SampleAns@

.-t -'l

.J

1. 'X 'markis drawnon a pieceof whiteifilter/ cardboard paper. 50 cm3of sodiumthiosuphate solutioni(0.01-1.0) moldm-31 is measured with a (50 cm3) measuring cylinderandis pouredintoa conicalflask. 3 . The solutionis slowlyheateduntil30 "C. 5 cm3of hydrochlorii acidt(0.1-2.0)moldm-31 is -. with a (10cm")measuring cylinderand is measured addedto the conicalflask.A stop-watchis started immediately is swirledand is placedon a 5. The conicalflask paperwith a mark'X'. whiteifilter/cardboard The'X' markis observedverticallyfromthe top throughthe solution. -7 The stop-watchis stoppedimmediately whenthe 'X' is recorded, markcannotbe seen.Time The experimentis repeatedby usingthe sodium thiosuphate solutionat 40 oC,50 oC,60 oCand70'C

l

I

r p cn cr - iir r e h r

Able to listdown sfeps 2, 4, 5, 7, I

2

Ableto givean ideato step4.

1

No responseor wrongresponse

0

': KUDnC

QueSlionNo.

2 (vi)

;

Score

Mle to tabulat&he data with followingaspecfs .:::

;-F-

1. Correcttitlffirith units 2. Completelistof temperatures Sample answer: Temperature

("c)

Time (s)

Z

5U

40 60 70

Able to contructa table. 1. At least1 titlescorrectwithoutunits 2. lncompletelistof tempereatures Sampleanswer:

Temperature 30

No responseor wrongresponse

1

0

r7

:€

in:'

Exp#nent2:2H&+ 7n ) ffiL. + H, €uestionNo. t -:.

--

lt l

Rubric Able to gi-vethe stalement of the probf@accurately. Responseis in questionform.

Sco_re

Sampleanswer: acid solutionaffectthe Doesthe temperatureof hydrochloric rateof reaction? ll Howdoesthetemperature of hydrochloric acidsolution affectthe rateof reaction?i/ Howdoesthe high/ low temperature of solutionaffectthe ratehvdrochloric acid of reaction? Able to give the statementof the problem |essaccurately. Responsein questionform. Sampleanswer: Doesthe increase/ decrbasein temperature increase/decrease the rateof reaction?i/

z_

in temperatureaffectthe Howdoesthe increase/decrease rateof reaction? Able to give an idea of statementof the problem. Sampleanswer: Does temperatureaffectthe rate of reaction? will increase The increaseidecrease in temperature /decreasethe rate of reaction.//

1

will increase/decreasethe The higher/ lowerin temperature rateof reaction.// To investigate to the rate of the effectof temperature reaction. No response or vlrone response

0

ffi:estionNo. = 2 (ii) .& .

-r=:

lSbric Ableto statethe threevaia5lesconecil{ .:--:=bampreanswer:

Score

'&

:-

Manipulated Variable. Temperature of hydrochloric acid Responding variable: Rateof reaction// Volumeof gas per unittime Constant variable: Mass/sizeo'fzincll Volumeandconcentration of hvdrochloric acid Able to stateany two variablescorrecily

2

Able to stateany ane vaiables correcfly

1

Noresponseor wrangresponse

n

19

Questio@o. z ( lllF

E Ru b ric + Able tostate the relationshipcorrectlybetween theF manipttWedvariableand the responclingvariablewith directiffi : .Sampleanswer: The higher/lower the temperature of hydrochloric acid,the higher/lower rate the of reaction./l

core

Thehigher/lower the temperature of hydrochloric acid,the higher/lower the volumeof the hydrogengas releaseper unittime /l The increaseldecrease in temperature of hydrochloric acid willincrease/decreadb the rateof reaction.// Whenthe temperatureof hydrochloric acid increases/decreases, the rateof reactionwill increase/decrease. Able to stafethe relationshipbetweenthe manipulated variableand the respondingvariablewith direction. Sampleanswer: The higher/lower the temperature, the higher/lower the rate of reaction.// z

The higher/lower the temperature, the higherilower the volumeof the hydrogengas releasedper unittime. // The increase/decrease in temperature will increaseidecrease the rateof reactions.// Able to statethe idea of hypofhesis. Sampleanswer; Differenttemperature,differentreactivity.i/

1

Temperature changes,the time takenis different.

Noresponse or wrongresponse

0

20

Ru b ric

2 (iv) -

| AOieto g@ completelistof mateialsand apparatuf I Sampleanswer: Materials: acid Zinc,hydrochloric A

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/- 1^^^-^1, PPclrcr [u 5 .

Conicalflask,thermometer , bunsenburner,stop-watch tubeandstopper, measuring cylinder(50 ml),delivery burette.basin. Able to give all mateialsand five apparatusas following. Answer: Materials: acid Zinc,hydrochloric A pparatus: bunsenburner,deliverytube, Conicalflask,thermometer, burette Able to give at leastone subsfanceand at leastone apparatus.

tVoresponseor wrongresponse

2l

QuestionNo,

2 (v)

-+

-+

Rubfr

+Score

Able to list all fhe:ffeps correctly*

saffiteAniwer: 1-, Buretteis filledwithwaterandinvertedinto a basin containing water. 2. The buretteis clampedverticallyusingretortstand. 3. lnitialreadingof buretteis recorded. 4. t20-501 acid [(0.01-1.0) mol cm'of hydrochloric witha (50ml) measuring cylinder dm{l is measured poured into a flask. and is conical 5. The solutionis slowlyheateduntil30 "C. 6. 2 g of zincis weighed,and is put intothe conical -- flask. is closedimmediately with a 7. The conicalflask stopperwhichis joinedto the deliverytube and the stopwatchis started. B. The burettereadingis recordedat intervalof 30 secondsuntilthe reactionis completed. 9. The experimentis repeatedby usingthe hydrochloric acidat 40'C, 50 oC,60 oCand 70 oCrespectively. Able to listdown steps 1. 4, 6, 8, I Ableto givean ideato step6.

No responseor wrongresponse

z

1 tl

22

QuestionNo. 2 (vi)

Rubric +

Score

datawithfo|Iow@aspects AbIeto-tabulat€the 1. Correcttitteswith units 2. Completelistof temPeratures Sampleanswer: Temperature \ \,/

Time (s)

2

JU

-40 bU

70

Able to contructa table. 1. At least 1 titlescorrectwithoutunits 2. lncompletelistof tempereatures Sampleanswer: Temperature 1 JU

No responseor wrongresponse

0

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