8/6/2019 F334 JAN 10 - MS (New Spec)
1/13
F334
Mar
kScheme
January2010
F334
ChemistryofM
aterials
Question
E
xpectedAnswers
Marks
AdditionalGuidance
1
(a
)
2-hydroxypropanoicac
id
2
markindep
endently
2-hydroxy
DONOTA
LLOW
hydroxyl
propanoicacid
ALLOWifpropan-and-oicareseparated
.
(b
)
(i)
(enantiomersare)isom
erswhosestructuresaremirror
imagesofoneanother
andarenon-superimposable
2
markindep
endently
mirrorimag
es
non-superimposable
IGNOREreferencesto4differentgroups
aroundaC
atom,optic
alisomerism,variouschiralwo
rds&rotationof
planepolarisedlight
(ii)
OH
HOOC H
3C
H
OH
COOH
CH3
H
2
3Dstructurecorrectforoneisomer
DONOTA
LLOW9
0or180degreeangle
sbetweenthe
twobonds
intheplaneofthepaper
mirror-imagecorrect(musthave4bonds
aroundtheC)
ALLOWec
ffornon3Dstructurewithfourdifferent
groupsonly
IGNOREth
ewaythegroupsarebondedtocarboneg
-OHorHO,sameforCOOH&CH3
(c)
(i)
P=C
Q=A
R=B
1
21
8/6/2019 F334 JAN 10 - MS (New Spec)
2/13
F334
MarkScheme
January2010
Question
E
xpectedAnswers
Marks
AdditionalGuidance
(ii)
P=(C)doesnotfizz/
doesnotreact/withNa2CO3A
NDso
noCOOHgrouppres
ent/AW
Q=nophenolgroup(inA),soFeCl3remainsyellow/AW
R=(Bhas)bothphen
ol&carboxylicacid(COOH)(sowill
turnFeCl3purpleandwillfizzwithNa2CO3)/AW
Thewordsinbracketsareonlyneedediftestsno
t
discussedforP&Q.
3
ifanswers
to(i)areincorrect/noresponse
award1mark
forcorrect
answersforhavingbothtests
forphenoland
carboxylicacid:
ie:purplesolu
tion=phenol
ANDacids
fizzwithcarbonate
IGNOREP
isCasitturnsFeCl3purple
IGNOREQ
isAasitfizzes&istherefore
acarboxylicacid
(d)
C
because:
(broad)peakataround
3250(cm1)indicatesalcohol
or
phenol/OH/hydroxylgroup
nopeakat17001725
(cm1)sonoC=O(inCOOH)
present
3
IGNOREa
nyreferencetocarboxylicacid
forthe3250
peak
ALLOWa
rangearound3250
Peaksmay
beidentifiedonthediagram
IGNOREa
llotherpeaks
(e)
(i)
nucleophilicaddition
2
nucleophilic
addition
markindep
endently
22
8/6/2019 F334 JAN 10 - MS (New Spec)
3/13
F334
MarkScheme
January2010
Question
E
xpectedAnswers
Marks
AdditionalGuidance
(ii)
O
O
CN
CN
4
curlyarrowshowingattackbyCNatC=
Ocarbon
DONOTA
LLOW
arrowstartingfromNofCN/single-
headedarr
owsbutgive1markifbothare
singleheaded
butotherwisecorrect
C=Obond
polarisedcorrectly
curlyarrow
showingmovementofdouble
bond
finalstructurecorrectALLOWanycorrectstructural
formulanotjustskeletal
OMUSTbeve
IGNOREa
nyfurtherreactionshowingOgainingH+
(iii)
theratedeterminingstep(slowstep)doesnotinvolve
water
(since)waterdoesnot
appearintherateequation/w
ateris
zeroorder
Sincewater/H+requiredtoformproductitmustreactina
subsequent(fast)step
/theremustbeatleast2steps
inthe
reaction/AW
OR
theratedeterminingstep(slowstep)onlyinvolvesethanal&
cyanide
(becauseonly)ethana
l&cyanideappearintherate
equation
andsowatermustrea
ctinasubsequentstep
3
23
8/6/2019 F334 JAN 10 - MS (New Spec)
4/13
8/6/2019 F334 JAN 10 - MS (New Spec)
5/13
F334
MarkScheme
January2010
Question
E
xpectedAnswers
Marks
AdditionalGuidance
2
(a
)
Fe
3+willoxidiseCu/O
RA
ORCuloseselectronstof
ormCu
2+/ORA
becauseelectrodepo
tentialofFe3+/
(Fe2+)ismore
positive/ORA(involv
estheCopperhalf-cell)
ORUsesEcellcalculationtoshow
reactionisfeasible
Cu+2Fe
3+
Cu
2++
2Fe
2+
3
ALLOWFe(III)andCu(II)
DONOTA
LLOW
electronegativityorhigher/loweror
larger/smaller
IGNOREstatesymbols
(b
)
(i)
PtelectrodeforFe
3+/
Fe
2+halfcell
inFe3+/
Fe2+
CuelectrodeinCu
2+
saltbridgelabelledandinsolutions
conditions:1moldm3
and298K/25C
5
ALLOWCuSO4etc.insteadofCu
2+
ALLOW1
molar/1M
(ii)
0.43V
1
IGNOREa
nysign
(c)
(i)
Copper(I)iodide
1
DONOTA
LLOWcopperiodide
ALLOWC
opperIiodide
25
8/6/2019 F334 JAN 10 - MS (New Spec)
6/13
F334
MarkScheme
January2010
Question
E
xpectedAnswers
Marks
AdditionalGuidance
(ii)
1.molesofthiosulfate
=0.200x(20.5/1000)=0.0041
2.(molesofiodine(I2)
=0.5xanswerfrom1(0.0041
)and
molesofCu
2+(aq)in25.0cm
3=
2x0.5xanswer
from1(0.0041))=0.0041
3.molesofCu
2+(aq)in
250cm3=
10xanswer
from1(0.0041)=0.04
10
4.massofCuincoin=
answerfrom3(0.0410)
x63.5=2.6035g
5.%ofCuincoin=(answerfrom4(2.6035)/3.47)
x100=75.0
6.(3sig.figs.)
6
75.0withn
o/incompleteworkingscores6marks.
Themarks
areawardedfortheworkingoutgivenin
bold:
Iffinalanswerisincorrectpleaseannotatemarksgiven
withticksA
NDcrosseswhereerrorshave
occurredeg
missingou
tstep3.
1.molesofthiosulfate=0.0041moles
2.correctm
olesofCu
2+(aq)in25.0cm
3e
cffrom1
3.molesofCu
2+(aq)in250cm3=
10xm
olesof
thiosulfa
te
4.massof
Cuincoin=molesofCu
2+(aq)
in250cm3
x63.5
5.%ofCu
incoin=massofCuincoinx100
6.correct/incorrectanswerMUSTbegive
nto3sig
figs.
Steps3&
4maybeinadifferentorder
(d)
(i)
(transmits)Blue
Cu
2+(aq)absorbred/
orangelight
QWCabsorb(s)/absorbing/absorption/absorban
ce/
absorbed
Oneofthesewordsha
stobeusedtogainthesecondmark
andspellingmustbec
orrect
2
IGNOREp
ale,deeporlightetc.referring
toblue,reflects
DONOTA
LLOW
green
ALLOWco
mplementarycolour/specificfrequencies/
wavelength
soflightareabsorbed
DONOTA
LLOW
allotherfrequencies/c
olour/AW
Useofem
itisaCONforthe2ndmark
26
8/6/2019 F334 JAN 10 - MS (New Spec)
7/13
F334
MarkScheme
January2010
Question
E
xpectedAnswers
Marks
AdditionalGuidance
(ii)
Ligandsubstitution
[CuCl4]2
2
ALLOWlig
andreplacement/displacement/exchangeor
complexfo
rmation
Thecharge
isrequired
ALLOW[C
u(H2O)2Cl4]2
(iii)
Anyfivefroma-f:
a.makeupstandards
olutions/ofknownconcentrations(of
Cu
2+(aq))
b.chooseasuitablefilter/setthecolorimetertoasuitable
wavelength
c.zerocolorimeterwithwater/solvent/AW
d.measureabsorbance/absorptionofstandardso
lutions/
AW
e.plotcalibrationcurve
f.measureunknown
AND
g.QWC
readoffconc
entrationfromcalibrationcurve
/AW
6
IGNOREtr
ansmittance
Total
26
27
8/6/2019 F334 JAN 10 - MS (New Spec)
8/13
F334
MarkScheme
January2010
Questio
n
Ex
pectedAnswers
Marks
AdditionalGuidance
(a)
(i)
O
O
H
O
P
HO
O O
OH
2
thelinkbetweenphosphategroupandan
yOHgroupon
thesugar
ieP-O-CH2-C(inringnexttoO-)
orP-O-C(inring)dependingwhich-OHg
roupisused
correctlink
age(P-O-CH2-C)andrestofstructurecorrect
3
(ii)
Water/H2Oandconden
sation(reaction)
1
(iii)
N
NN
O
H
H
H
1
ALLOW
ALLOWif
theN-Hgroupiscircled
(iv)
lonepair(ofelectrons)onN/amine(group)
acceptsaproton/H+
2
N
O
HN
H
H
28
8/6/2019 F334 JAN 10 - MS (New Spec)
9/13
F334
MarkScheme
January2010
Questio
n
Ex
pectedAnswers
Marks
AdditionalGuidance
(b)
N
N
N N
N
H
H
3
2hydrogen
bondscorrect
DONOTA
LLOW
morethan2bonds
correctpolarities(all3)ononegroupofa
toms
lonepairontheNORO
(c)
twostrands(notthree)
phosphategroupsonthe
outside(notontheinside)
basesfaceintothecentr
e(nottheoutside)
3
ALLOWdo
ublehelix
IGNOREp
hosphatebackbone
(d)
forremoval:
infringementofpersonal
liberty/AW/
'fingerprint'notuniqueon
lyprobability/
techniquesusednotfoolproof/
law/typeofgovernmentmightchangechangingacces
sibility/
AW
againstremoval:
helpstosolvemanycrim
es,particularly'cold'crimes/
'innocentuntilprovedguilty'/AW
futureresearchintodisease
2
IGNOREh
ackingintodatabase/leakage
ofdata
(NOTE:probabilitymayonlybe1in20forsome
population
groups)
29
Total
14
8/6/2019 F334 JAN 10 - MS (New Spec)
10/13
F334
MarkScheme
January2010
Question
ExpectedAnswers
Marks
AdditionalGuidance
(a)
Cl
HN
O
2
1markfor
eachstructurecorrect
DONOTA
LLOWm
issingHatomsifstructuralformulae
aredrawn
4
(b)
(i)
thereare(two)differentgroupsoneachcarbonofaC
=Cin
neoprene
thesegroupscannotrotateaboutthedoublebond
2
Maybeshowninadiagram
ALLOWre
stricted/limitedrotationabout
thedoublebond
(ii)
(lesstranslinkages)w
illmakethechainslesslinear/less
regular/lessordered/
ORA
sotheycannotlineup
/bearrangedsoregularly/clo
sely
andthecrystallinitywillbereduced
2
ALLOWch
ainshaveakink/aremorerandomlyarranged
Note:
1st markis
forshapeofchain,
2ndmarkis
forrelativearrangementofchains.
(c)
CONHgroup/NHgro
up/amidegroupallowsnylon
toform
hydrogenbondswithw
atermolecules
nohydrogenbondinginneoprene
watermoleculeswillforcechainsfurtherapart/chainswillnot
fitascloselytogether/
AW
chainslesscrystalline/weakerintermolecularforcessoTgwill
belowered
4
IGNOREc
hainsslidingovereachother
30
8/6/2019 F334 JAN 10 - MS (New Spec)
11/13
F334
MarkScheme
January2010
Question
ExpectedAnswers
Marks
AdditionalGuidance
(d)
H2N
O
O
Na
2
6carbonatomsandNH2group
COO
ALLOWsk
eletaloranyequivalent/altern
ativestructural
formula
DONOTA
LLOWs
tructureswithmissing
Hatoms
Total
12
31
8/6/2019 F334 JAN 10 - MS (New Spec)
12/13
F334
MarkScheme
January2010
Question
E
xpectedAnswers
Marks
AdditionalGuidance
(a)
(i)
3H2S+2MnO4
+
2H+
2MnO2
+3S+4H2O
1
all4numbersMUSTbecorrect
5
(ii)
oxidationstate=+4
1
DONOTA
LLOW
4+OR4
(b)
(i)
iron(III)hydroxide
1
DONOTA
LLOWironhydroxide/Fe(OH)3
(ii)
Fe
3+(aq)+3OH(aq)
Fe(OH)3(s)
2
equationcorrect
statesymb
olscorrect
ALLOWec
fforiron(II)hydroxidein(i)
(c)
(i)
Thelargeexcessofethanedioateandacidmeansthattheir
concentrationswerevirtuallyconstantduringthereac
tion/
concentrationshardlychanged/concentrationswere
highso
littleeffectonrate/AW
1
Alargeex
cessofethanedioateandacid
byitselfdoes
notgetthe
mark
IGNOREe
xcessethanedioateandacidn
otlimittherate
ofreaction/AW
Lookforco
ncentrationinanswer
(ii)
Oneofthefollowing:
Method1half-lives
determinationofatlea
sttwohalf-lives,13-15s
half-lifeconstant
firstorder
OR
Method2findingrateatdifferentconcentrations
calculationofatleastt
worates
rateisproportionaltoconcentration
firstorder
3
Twovaluesforhalf-lifeMUSTbegiven
Workingm
ustbeshownaseitheracalculationorbylines
ongraph.
32
8/6/2019 F334 JAN 10 - MS (New Spec)
13/13
F334
MarkScheme
January2010
33
E
xpectedAnswers
Marks
AdditionalGuidance
Question
(iii)
3d
4s
1
(d
)
Onefromthefollowing
:
lossofCO2/CO2
prod
ucedbyweighing/gascollection/
measuringmilkinesso
flime-water
OR
titrationofMnO4
wi
th(standard)Fe
2+(aq)
OR
titrationofH+(aq)decreasew
ithOH/
CO3
2(aq)
OR
measurepHchangeH
+ionsusedinthereaction
2
Thetwopa
rtsaremarkedindependently
ALLOWga
sforCO2andmeasuringvolum
eforgas
collection
Total
12