8/12/2019 4CH0_1C_msc_20130823

1/33

Mark Scheme (Results)

Summer 2013

International GCSEChemistry (4CH0) Paper 1C

Science Double Award (4SC0)

Paper 1C

Edexcel Level 1/Level 2 CertificateChemistry (KCH0) Paper 1CScience (Double Award) (KSC0)

Paper 1C

8/12/2019 4CH0_1C_msc_20130823

2/33

Edexcel and BTEC Qualifications

Edexcel and BTEC qualifications come from Pearson, the worlds leading learningcompany. We provide a wide range of qualifications including academic, vocational,occupational and specific programmes for employers. For further information visit ourqualifications websites at www.edexcel.com or www.btec.co.uk for our BTEC

qualifications.Alternatively, you can get in touch with us using the details on our contact us page at

www.edexcel.com/contactus.

If you have any subject specific questions about this specification that require the help

of a subject specialist, you can speak directly to the subject team at Pearson.Their contact details can be found on this link: www.edexcel.com/teachingservices.

You can also use our online Ask the Expert service at www.edexcel.com/ask. You willneed an Edexcel username and password to access this service.

Pearson: helping people progress, everywhere

Our aim is to help everyone progress in their lives through education. We believe in

every kind of learning, for all kinds of people, wherever they are in the world. Weve

been involved in education for over 150 years, and by working across 70 countries, in

100 languages, we have built an international reputation for our commitment to high

standards and raising achievement through innovation in education. Find out more

about how we can help you and your students at: www.pearson.com/uk

Summer 2013

Publications Code UG037094

All the material in this publication is copyright

Pearson Education Ltd 2013

8/12/2019 4CH0_1C_msc_20130823

3/33

Question

numberAnswer Notes Ma

1 (a) i 5

ii 11

iii 5

iv 6

v 5

1 (b) i more

ii more

iii the same number of

1 (c) cross in box D (2.8.3)

Total

8/12/2019 4CH0_1C_msc_20130823

4/33

Question

numberAnswer Notes M

2 (a) i cross in box A (zinc sulfate)

iicross in box B (iron)

cross in box C (magnesium)

Apply list principle - 3 crosses = max 14 or 5 crosses = 0 marks

2 (b) burns with a pop/squeakORuse burning/lit splint/flame tosee if pop/squeak

Must be reference to test and resultReference to splint/match with noindication of flame is not enoughReject reference to glowing splint

Ignore flame extinguishedSqueaky pop test on its own is not

sufficient

2 (c) 2 (1) 2 Accept multiples and fractions

2 (d) i

ii

cross in box 3

reversible / can go in bothdirections

/ can go backwards andforwards

Ignore references to equilibriumIgnore references to other reactiontypes (e.g. hydration / oxidation /

exothermic)Accept either equation with

Total

8/12/2019 4CH0_1C_msc_20130823

5/33

Question

numberAnswer Notes

3 (a) i gas / (g) / g Accept equivalentssuch as gaseous /

vapourIgnore colours

ii darker / dark grey Accept blackIgnore references states

Ignore more intenReject reference to

any other colours

8/12/2019 4CH0_1C_msc_20130823

6/33

Questionnumber

Answer Notes

3 (b) i no reaction (possible) / no

displacementOR

halogens do not react withtheir own halide ions

Accept no change

Ignore references to lithium chloride containingchlorine / already reacted / OWTTE

ii

iii

iodine/it is less reactivethan bromine/ bromine more reactivethan iodine

iodine

Accept correct references to positions in (re)activityseriesBoth halogens must be mentioned, except assume refers to iodine

Reject ide endingsAccept symbols and formulae

Ignore references to only one element, e.g. iodine unreactiveReject any comparison involving sodium

Ignore references to states

Ignore I and I2iv

v

cross in box D (brominedisplaces iodine)

2KCl + Br2 Either order

Penalise incorrect symbols/numbers / unconventionformulae in this part, e.g. CL, br, Br2, ClK

To

8/12/2019 4CH0_1C_msc_20130823

7/33

Questionnumber

Answer Notes

4 a 4 electrons shared between 2 (carbon)atoms

Ignore inner electronseven if wrong Ignore

number of hydrogenatoms

4 electron pairs between 2C and 4H atoms Accept all permutation

dots and crossesIgnore intersecting cir

Accept H atoms at allanglesAt least one C or one Hatom must be labelled

max 1 if notMax 1 if more than 2 C

atomsMax 1 if wrong numbeelectrons in outer shel

any atom

8/12/2019 4CH0_1C_msc_20130823

8/33

Questionnumber

Answer Notes

4 b i setting out correct division of each %byAr

OR3.2, 9.7 and 3.2

Award 0/3 if division by any atomicwrong way up / multiplication used

Do not penalise roundings and minoof % values, eg 38 or 39 for carbonIf molecular masses used for H and

M1, but can award M2 and M3but no CQ in iiUsing 2 and 32 gives C2H3OUsing 1 and 32 gives C2H6O

Using 2 and 16 gives C2H3O2Working required for these answers

division by smallest /ratio of 1 : 3 : 1 M2 subsumes M1

CH3O Accept elements in any orderAward 3 for correct final answer witworkingNo ECF from M2

Accept use of 62 from ii,i.e. 62 0.387 = 24 etc scores M1ratio scores M2, answer scores M3

ii C2H6O2 Accept elements in any order

No other answer acceptable

8/12/2019 4CH0_1C_msc_20130823

9/33

Questionnumber

Answer Notes

5 a i haematite Ignore iron oxide / formulae

ii

iii

Al2O3/ Al3+2O23

carbon / C

(positive/negative) electrode

Ignore reactants in equation

Accept graphite

Ignore coke / anthraciteDEP on M1 (including coke or any m

Accept anode / cathodeAccept references to lettingelectrons/electricity/current flowAccept references to letting

electrons/electricity/current in/out

cell/electrolyteIgnore references to attracting ionsAccept references to conducting eleIgnore references to electrolysisIgnore references to burning or com

oxygenIgnore references to reduction/oxid

8/12/2019 4CH0_1C_msc_20130823

10/33

Question

number Answer Notes 5 iv oxygen / O2 Accept O

Ignore airproduction of heat/maintaining temperature

of furnaceOR

formation of reducing agent/carbon monoxide

DEP on mention of

oxygen/O2/O/airIgnore

combustion/oxidation/reof carbon/cokeIgnore references toincreasing temperature o

furnace

8/12/2019 4CH0_1C_msc_20130823

11/33

Question

numberAnswer Notes

5 (b) i redox

ii

iii

(it/ Al3+/aluminium ions) gain of electron(s)OR

Al3+combines/reacts with electrons

C / carbon

gain of oxygen / O / O2OR

reacts/combines/joins/bonds with oxygenor O or O2ORreduces water/H2O

Reject gain of electronby Al/aluminium

Accept decrease in

oxidation stateIgnore/ references to gof oxygen

Accept graphite/coke

DEP on M1Ignore forms carbon

monoxideIgnore references to loof electronsAccept increase in

oxidation stateIgnore (acts as) reduciagent

8/12/2019 4CH0_1C_msc_20130823

12/33

Question

numberAnswer Notes M

5 c i (a substance that)increases rate of reaction /

speeds up reaction /decreases time of reactionis (chemically) unchanged(at the end)

ORmass does not change

Accept is not used up / does not changeAccept reference to lowering activation

energyIgnore reference to alternative route

Ignore references to yieldIgnore reference to not reacting or takingpart in reactionReject reference to providing/increasing

energy

Reject reference to incorrect statement suchas removes impurities

ii (acts as) solvent (foralumina/aluminium oxide)

ORto lower the (operating)temperature

Accept to lower melting point (ofmixture/electrolyte)

Reject to lower melting point ofalumina/aluminiumoxide/aluminium/bauxiteAccept to reduce (heat) energy requirement

Accept to increase the conductivity of themixture/electrolyte/alumina

Reject acts as a catalyst

8/12/2019 4CH0_1C_msc_20130823

13/33

Questionnumber

Answer Notes Ma

5 d i Fe2O3 + 3CO 2Fe + 3CO2 M1 for correct reactants

and products

M2 for balancing

M2 dep on M1

ii neutralisation Accept acid-base

Ignore all otherdescriptions

iii slag

Total 1

8/12/2019 4CH0_1C_msc_20130823

14/33

Question

numberAnswer Notes M

6 (a) C Accept formula of C

6 (b) i (compound/molecule/substancecontaining) carbon and hydrogen

(atoms/elements)

Reject atom/element in place ofcompound/molecule

Reject compound/molecule in place ofatoms/elements

Reject mixture

Only

A

M2 dependent on mention of carbonand hydrogen even if M1 not awarded

Accept other terms with samemeaning, e.g. solely / exclusively /just

M3 independentAccept name/formula of A

ii contains a (C=C) double bond Accept multiple bond

Ignore references to type ofcompound, eg hydrocarbon

Reject double bond between C and HDo not penalise incorrect terms suchas atom or elementIgnore not all bonds are single

Accept can undergo addition reactionsAccept does not contain the

maximum number ofhydrogens/hydrogen atoms

B M2 independent

Accept name/formula of B

8/12/2019 4CH0_1C_msc_20130823

15/33

Answer Notes M

6 b iii (compounds / molecules / substances with)

same molecular formula / same number ofeach type of atom

Ignore same (chemical)

formula /same compoundNo penalty for reference tohydrocarbons

Reject sameempirical/general formulaIf atoms or elements insteadof compounds or molecules,

only 1 of M1 and M2 can beawarded

different structures/different structural/displayed formulaeOR

atoms arranged differently

Ignore different moleculararrangement

C and F Accept in either orderAccept formulae of C and F

8/12/2019 4CH0_1C_msc_20130823

16/33

Questionnumber

Answer Notes

6 c i same/similar chemical

properties/reactions/behaviour/characteristics

Ignore specific examples such

with oxygenIgnore similar (type of) reactiv

Do not penalise reference to tr

gradation / gradual change / trend / increase

/ decrease of physical properties

Accept reference to specific pr

boiling pointReject same / similar physical Ignore variable physical prope

same functional group Ignore reference to specific gr

same general formula Accept alkanes have the (geneCnH2n+2Reject same empirical/molecu

Any two for 1 each

Accept two answers on one anIgnore any reference to propespecified as physical or chemic

ii D AND E Reject any other combinations

Accept correct formulae

8/12/2019 4CH0_1C_msc_20130823

17/33

8/12/2019 4CH0_1C_msc_20130823

18/33

Questionnumber

Answer Notes

7 a reference to line/curve/temperature

/graph/itANDnot reached minimum / not constant / not

level/not horizontal /still falling/decreasing/changing

Ignore reference to correlation

Ignore has not reached zero / Ignore does not become

b (better) insulator (than glass)ORpoor conductor (of heat)

Accept equivalents such as preentering / keeps out heat betteAllow stops heat escaping / tra

Reject references to keeping teIgnore references to breaking

c i effervescence / fizzing / bubbles

ORcolourless solution/liquid formed

Accept carbon dioxide gas

Accept gas given off/evolved/fIgnore identity of gasAccept solid disappears/dissolv

Ignore hissing and other sound

ii Neutralisation Accept acid-base / acid-alkali

endothermic M1 and M2 independentAccept answers in either order

Do not penalise contradictions and endothermic this answer

8/12/2019 4CH0_1C_msc_20130823

19/33

Question

numberAnswer Notes

7 d i product formulae or names /products (word) above

reactants

Horizontal line not neededIgnore formula errors and one or

two missing product(s)Ignore curves and intermediates

ii (approximately) vertical line

between reactants andproducts / between two levelsAND

labelled H/ energy change /heat change / enthalpy change

Ignore arrowheads on vertical line

Ignore sign of HMark can be awarded forexothermic reaction

Accept 2310 or any other numberin place of H

8/12/2019 4CH0_1C_msc_20130823

20/33

Questionnumber

Answer Notes

7 (e) i temperature change = ()5.5(C)

Award M1 for 5.5 anywhere

heat change (= 100 4.2 5.5) = 2310/2300 (J)

CQ on candidate temperaturechange, provided other values

correctAccept answer in kJ

Ignore signsCorrect final answer scores 22.31 (J) scores 1 mark if M1 notawarded

ii concentration (of vinegar /(ethanoic) acid / CH3COOH)

Ignore strengthIgnore reference to MrAccept concentration even if in anincorrect expression

Total

8/12/2019 4CH0_1C_msc_20130823

21/33

Questionnumber

Answer Notes

8 (a) mass Accept weight surface area / size / volume Ignore length / width / height /

thickness / shape / typeIgnore temperature / purity /

density

8 (b) (2) time / how long (to

collect gas)

(3) number of / how many(marble) chips

(4) volume of gas / how

much gas collected

(5) percentage /concentration (of acid)

Accept length of

reaction/experiment

Ignore amount of marbleAccept amount of (marble) chips

Accept carbon dioxide/CO2in place

of gasAccept amount of gas

Accept strength (of acid)

Ignore volume of acidReject amount (of acid)

8/12/2019 4CH0_1C_msc_20130823

22/33

Questionnumber

Answer Notes

8 (c) i all six points plotted to nearest

gridline

Deduct 1 mark for each error up to ma

extra points, but no penalty for point a

straight line of best fit Line need not be extrapolated

Must be drawn with a rulerCQ on candidates plotted points

ii anomalous point circled at 1.5, 20 or CQ on candidates line of

iii timer started late / stopped early

concentration/% too high/more

than 20%marble chips bigger / moremarble chipsair in measuring cylinder before

experiment started(room) temperature higher

Ignore just wrong time

Ignore just wrong concentration

Ignore just wrong mass/size

Accept smaller volume of gas collected

vertical line from 50% to drawngraph line

2.4 (cm3/s)

Ignore references to calculation

Any two for 1 mark eachM1 to M5 CQ on position of anomalous anomalous point below line of best fit,

M1 timer started too early/stopped too M2 concentration/% too low/less than M3 marble chips smaller / fewer marbleM4 larger volume of gas collected

M5 (room) temperature lower

Accept short vertical line crossing graphAccept point on graph line at 50%

CQ on drawn graph line but can be awavertical line

Do not penalise incorrect units

iv

8/12/2019 4CH0_1C_msc_20130823

23/33

Questionnumber

Answer Notes

9 (a) i beaker Ignore qualifiers such as measuring/ graduated / 250 cm3

ii Pipette Ignore qualifiers such as measuring/ graduated / 25 cm3

iii colour change is gradual /notsharp/not definedOR

end point not sharp/defined/accurate

methyl orange / phenolphthalein /litmus

Ignore reference to many colours

Accept other correct indicatorsIgnore reference to pH meterReject litmus paperIgnore named colours and colour ch

iv (measures) only one volume / fixedvolume / 25 cm3

has only one graduation markORcannot deliver (measured) variablevolume

ORvolume required is not knownOR

cannot be controlled / hard to control

Ignore reference to accuracy / sizeAccept reverse arguments based on

burette, eg burette can deliver/meavolume

8/12/2019 4CH0_1C_msc_20130823

24/33

Questionnumber

Answer Notes

9 (b) (after) 22.60

(before) 2.75

(added) 19.85 CQ on before and after readingsAward 1 for before and after

values both correct but in wrongorderAll values must be to 2 dpPenalise answers to other than 2

dp once only

8/12/2019 4CH0_1C_msc_20130823

25/33

Questionnumber

Answer Notes

9 (c) i ticks in columns 3 and 4

ii 23.35 + 23.452

CQ on ticked resultsIf no results ticked, award M1 if

only columns 3 and 4 averagedIf only 1 result ticked, then nomarks can be awarded in (c)

23.4(0) CQ on results averaged

Answer should be to 2 dp, exceptthat trailing zero not needed

Correct final answer withoutworking scores 2

8/12/2019 4CH0_1C_msc_20130823

26/33

Questionnumber

Answer Notes

9 (d) i divide/ by 1000 (not by

100)OR

convert volume/cm3to dm3OR

use 1000 instead of 100

Accept 0.0500 23.60 (=

0.00118 mol)1000

Accept divide (final) answer by 10

ii multiply/ (amount of H2SO4)by 2 (not divide by 2)

Accept 0.(0)0118 2 (=0.0(0)236 mol)Accept any other number in place

of 0.0(0)118Accept multiply (final) answer by 4

iii divide by 25.0 (not by 23.60)ORdivide by volume of KOH (not

by volume of H2SO4)OR

use 25.0/volume of KOHinstead of 23.60/volume ofH2SO4

Accept 0.00590 1000 (= 0.236mol)

25.0

Accept any other number in placeof 0.00590

Must be positive statement about

correction needed, e.g. in iii,ignore statement about volume of

H2SO4should not have been used

Total

8/12/2019 4CH0_1C_msc_20130823

27/33

Question

numberAnswer Notes

10 (a) air / atmosphere

10 (b) i (equilibrium / it) shiftsto left/reactants

Accept favours reverse reactionAccept less product/ CO + (3)H2/ lower yield

Accept more reactant / CH4+ H2Ofewer (gas)

moles/molecules onleftORfavours side with fewer

moles/molecules

Accept opposite arguments, eg more moles

rightIgnore references to volume and pressureAccept references to particles in place ofmolecules

Reject atoms in place of moleculesIgnore references to rate / collisions

If wrong shift, M2 cannot be awardedIf no shift, M2 can be awardedMarks can be awarded for both points in eithprediction or reason

ii (equilibrium / it) shifts

to left/reactants

Accept favours reverse reaction/less produc

Accept less product/ CO2+ H2/ lower yieldAccept more reactant / CO + H2O

(forward) reaction

exothermicORreverse reaction

endothermicIgnore references to rate

If wrong shift, M2 cannot be awardedIf no shift, M2 can be awardedMarks can be awarded for both points in eithprediction or reason

8/12/2019 4CH0_1C_msc_20130823

28/33

Questionnumber

Answer Notes

10 (c) Increased (rate) Accept alternatives such as fasterreactions

Increased (rate) Accept alternatives such as faster

reactions

Ignore references toequilibrium/yield

Ignore references to forward andreverse reactions

8/12/2019 4CH0_1C_msc_20130823

29/33

Questionnumber

Answer Notes

10 d i Mr(NH4NO3) = 80 Award M1 for 80 anywhere n (= 40000 )= 500 (mol)

80

ECF from incorrect Mr

500 scores M1 and M20.5 (mol) scores only M1

ii Answer to di / 500 (mol)

iii Mr(NH3) = 17 Award M1 for 17 anywhere, exceptif result of incorrect calculation

m = 500 17 = 8.5 (kg)1000

ECF from incorrect MrMoles CQ on ii

Accept answer in g if unit is givenIf no conversion from kg to g in i,and no conversion from g to kg iniii, penalise these errors once only

Award 2 marks for 8.5 (kg)

10 e phosphorus AND potassium Accept in either order

Ignore symbolsReject phosphate/phosphine

Total

8/12/2019 4CH0_1C_msc_20130823

30/33

Questionnumber

Answer Notes

11 a i delocalised electrons / sea ofelectrons

Ignore free electrons

move / flow (throughstructure) / mobile (whenvoltage/potential difference

applied)

M2 needs mention of electrons,e.g. "electrons move/flow" scoresM2 but not M1

Ignore references to carryingcharge/currentNo penalty for references toaluminium atoms or ions / nuclei /

protons, but any mention of thesemoving = 0/2

ii layers/sheets/planes/rowsAND(positive)

ions/atoms/particles

Reject

molecules/protons/electrons/nuclei

slide (over each other) Allowslip/flow/shift/roll/move/OWTTE inplace of slideDo not award M2 if no mention of

layers or equivalentDo not award M2 if

protons/electrons/nuclei

8/12/2019 4CH0_1C_msc_20130823

31/33

Question

numberAnswer Notes

11 b NITROGEN

(simple) molecular structure Accept (nitrogen/N2/small/discrete) molecu

intermolecular forces (of

attraction)/ forces between molecules

Accept intermolecular bonds

Reference to intermolecular also scores M1

weak / easily overcome

/need little energy toovercome

If any reference to breaking covalent bondsany other type of bonding, only M1 can beawarded

SILICA

giant (structure) Accept macromolecularIgnore lattice

covalent (bonds) Covalent can be anywhere in answer

bonds strong / hard to break/need a lot of energy to break

If any reference to breaking intermolecularforces or any other type of bonding, only Mcan be awardedAny five for 1 mark each

TTotal for pa

8/12/2019 4CH0_1C_msc_20130823

32/33

8/12/2019 4CH0_1C_msc_20130823

33/33

Further copies of this publication are available from

Edexcel Publications, Adamsway, Mansfield, Notts, NG18 4FN

Telephone 01623 467467

Fax 01623 450481

Email publication.orders@edexcel.com

Order Code UG037094 Summer 2013

For more information on Edexcel qualifications, please visit our website

www.edexcel.com

Pearson Education Limited. Registered company number 872828with its registered office at Edinburgh Gate Harlow Essex CM20 2JE