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1092
0100
01
ADDITIONAL MATERIALS
In addition to this examination paper, you will need a:• calculator;• Data SheetcontainingaPeriodic Table supplied by WJEC. Refer to it for any relative atomic masses you require.
INSTRUCTIONS TO CANDIDATES
Useblackinkorblackball-pointpen.Donotusegelpenorcorrectionfluid.
Writeyourname,centrenumberandcandidatenumberinthespacesatthetopofthispage.
Section A Answer allquestionsinthespacesprovided.Section B Answer allquestionsinthespacesprovided.
CandidatesareadvisedtoallocatetheirtimeappropriatelybetweenSection A (10 marks) andSection B (70 marks).
INFORMATION FOR CANDIDATES
Thenumberofmarksisgiveninbracketsattheendofeachquestionorpart-question.
Themaximummarkforthispaperis80.
Youranswersmustberelevantandmustmakefulluseoftheinformationgiventobeawardedfullmarksforaquestion.
The QWC labelalongsideparticularpart-questionsindicatesthosewheretheQualityofWrittenCommunicationisassessed.
If you runout of space, use the continuationpage at the backof the booklet, taking care tonumberthequestion(s)correctly.
SJJ*(S12-1092-01)
Surname
Other Names
CandidateNumber
2
CentreNumber
GCE AS/A level
1092/01
CHEMISTRY CH2
P.M. WEDNESDAY, 23 May 2012
1½ hoursFOR EXAMINER’S
USE ONLYSection Question Mark
A 1-6
B 7
8
9
10
11
12
TOTAL MARK
© WJEC CBAC Ltd.
PMT
2
(1092-01)
Examineronly
SECTION A
Answer all questions in the spaces provided.
1. Thestraight-chainalkanecontaining19carbonatomsiscallednonadecane.
(a) Write the molecularformulaofnonadecane. [1]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(b) Whennonadecaneiscracked,oneofthesmallerproductsformedcanbeoctane.
Writeanequationtoshowthecrackingofnonadecanetoproduceoctane. [1]
2. Namethecompoundwhoseformulaisshownbelow. [1]
H
H C C C C
H Cl
H H
H
H
H
H
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. Drawthedisplayedformulafor(Z)-2-iodobut-2-ene. [1]
4. Chlorineformsaseriesofoxidesthatreactwithwater.
SuggestapHvalueforthesolutionformedwhenanoxideofchlorinereactswithwater. [1]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
© WJEC CBAC Ltd.
PMT
(1092-01)
5. Asolidwaspreparedinanimpurestateanditwasthenpurifiedbyrecrystallisation.Thesolidwasdissolvedintheminimumamountofwaterat90°Candthesolutionwascooledto25°C.
Thesolubilitycurveforthesolidinwaterisshownbelow.
Turn over.
1092
0100
03
3 Examineronly
100
10
20
30
40
50
60
20 30 40 50 60 70 80 90
(a) Usethesolubilitycurvetofindthemaximummassofsolidthatwouldformfrom100gofsolutioncooledfrom90°Cto25°C. [1]
Maximum mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .g
(b) Whateffectwouldithaveonyouranswerto(a)ifmorehotsolventhadbeenusedtodissolvetheimpuresolid?Giveareasonforyouranswer. [1]
Solubility/gofsoluteper100gofsolution
Temperature/°C
© WJEC CBAC Ltd.
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6. Whenthetemperatureisincreased,bothsolidiodineanddiamondchangedirectlyintotheirgaseousstate–theysublime.
(a) Ineachcase,nametheforceorbondthatisbeingovercomewhenthesolidchangesintoagas. [2]
Iodine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diamond . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(b) State,withareason,whichsolidwouldhavethehighersublimationtemperature. [1]
Total Section A [10]
© WJEC CBAC Ltd.
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Examineronly
SECTION B
Answer all questions in the spaces provided.
7. Boron,B,hastheatomicnumber5anditformsafluoride,BF3.
(a) BF3isusedtoinitiatecertaintypesofadditionpolymerisationofunsaturatedcompounds.
(i) Etheneisanexampleofanunsaturatedcompound.Describethebondingbetweenthecarbonatomsinethene.Youmaywishtodrawalabelleddiagram. [2]
(ii) State what is meant by polymerisation. [1]
(iii) Acolourlessplasticusedtocoverlightsismadefrommethylmethacrylatebyaprocesssimilartothepolymerisationofethene.Completetheequationbygivingtheformulaoftherepeatingunit. [1]
CH3Hn CC
H CO2CH3
(iv) Additionpolymerisationisusedtomakesyntheticrubber.Themolecularformulaof the monomer used is C4H5C1. What is the empiricalformulaofthesyntheticrubberpolymer? [1]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
© WJEC CBAC Ltd.
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(b) (i) UsetheVSEPRtheorytodeducetheshapesofBF3andNH3. [2]
Shape of BF3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shape ofNH3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(ii) ExplainthedifferenceintheshapesofBF3andNH3. [2] QWC [1]
(c) Boron fluoride reacts with ammonia, NH3, to make the compound shown in thefollowingequation.
Turn over.
1092
0100
07
7 Examineronly
B N
F H
F
F
H
HBF3 + NH3
B N
F H
F
F
H
H
(i) NamethetypeofbondformedbetweenNandB. [1]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(ii) SuggestavaluefortheF–B–Fbondangleinthismolecule.
Bond angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [1]
(iii) Explainyouranswertopart(ii). [1]
Total[13]
© WJEC CBAC Ltd.
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8. (a) Compound Xisastraight-chainhydrocarbonthatconsistsof85.7%carbonbymass.
(i) Find the empirical formulaofcompoundX. [3]
(ii) SomepeaksfromthemassspectrumofX are shown below.
100 20 30 40 50
Usetheempiricalformulaandthemassspectrumtofindthemolecularformulaof X.Showyourworkings. [2]
(iii) Suggest what information the presence of the peak at m/z 15 gives about thestructureofX. [1]
m/z
Abundance
© WJEC CBAC Ltd.
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(1092-01)
(b) Butene, C4H8, is an alkene. Draw displayed formulae for three straight-chain isomers of C4H8. [3]
Total[9]
Turn over.
1092
0100
09
9 Examineronly
© WJEC CBAC Ltd.
PMT
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9. Calciumispresentinteethintheformofcalciumphosphates.Thesedonotreactwithwater.Theelementcalcium,however,reactswithwatertoproducecalciumhydroxideandhydrogengas.
Ca(s)+2H2O(1)Ca(OH)2(aq)+H2(g)
(a) Astudentinvestigatedthereactionbetweencalciumandcoldwater.Headded2.0gofcalciumtosomewaterandcollectedthehydrogengasformed.
Drawalabelleddiagramofanapparatusthatwouldbesuitableforcarryingoutthisreactionandmeasuringthevolumeofhydrogenproduced. [2]
(b) Thestudentrepeatedthereactionusingthesamemassofbarium.Henoticedthatthevolumeofgas,stillatthesametemperatureandpressure,wasless.
(i) Givethereasonwhythevolumeofgasproducedwasless. [1]
(ii) Suggestanotherdifferencethatthestudentwouldobservewhenbariumwasusedinplaceofcalcium.Explainyouranswer. [2]
(c) The studentdidnot label the flasks containing the solutionsafter the reactionswithcalciumandwithbarium.
Giveatestthatwoulddistinguishbetweenthesesolutions.Includetheresultofyourtestforbothsolutions. [2]
© WJEC CBAC Ltd.
PMT
(1092-01)
(d) Calciumoxidealsoreactswithwatertoproducecalciumhydroxide.Drawadotandcrossdiagramtoshowthebondingincalciumoxide.Showonlytheelectronsinoutershells. [2]
(e) Barium,asbariumsulfate,isusedmedicinallyinbariummealssinceitisinsolubleinwaterandshowsonx-rayimages.
(i) Starting from the solution of barium hydroxide the student produced in (b), describehowhecouldobtainapure,drysampleofbariumsulfate.
Youshouldincludeanionicequationforthereaction. [3]
(ii) Calculate the maximummass of barium sulfate that the student could make,startingwith2.0gofbarium. [2]
Mass = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .g
Total[14]
Turn over.
11 Examineronly
© WJEC CBAC Ltd.
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10. (a) Explainthefactthatthemeltingtemperatureofsodiumismuchlowerthanthemeltingtemperatureofmagnesium.
Youshouldincludereferencetothetype(s)ofbondinginvolvedandhowthisbondingaffectsmeltingtemperatures.Youmayincludeadiagramifyouconsiderithelpful.
[3]
(b) Inanexperiment,1-chlorobutanewasheatedwithaqueoussodiumhydroxideandtheresulting solutionwas acidified. Aqueous silver nitrate was then added and a whiteprecipitatewasobserved.
Theexperimentwasrepeatedusing1-bromobutaneandinthiscaseacreamprecipitatewasobserved.
Explaintheseobservations.
Youshouldinclude:
• thetypeofreactionthatoccursbetweenthehalogenoalkaneandsodiumhydroxide • anequationforthisreaction • theidentityofthecolouredprecipitates • anequationtoshowtheformationoftheseprecipitates. [4]
QWC [1]
© WJEC CBAC Ltd.
PMT
(1092-01)
(c) Describehowthestructuresofsodiumchlorideandcaesiumchloridearesimilarandhowtheyaredifferent.Giveareasonforanydifference.
Youmayincludeadiagramifyouconsiderithelpful. [3]
(d) Whenhydrogenbromide,HBr,isaddedtopropene,C3H6,twodifferentproductsarepossible.Inpractice,however,moreofoneoftheproductsisformed.
Explainwhymoreofoneproductisformed.
You should:
• statethetypeofreactioninvolved • identifythetwopossibleproducts • statewhichofthetwoproductspredominates • givethereasonwhymoreofthisproductisformed. [4] QWC[1]
Total[16]
Turn over.
13 Examineronly
© WJEC CBAC Ltd.
PMT
14
(1092-01)
Examineronly
11. Ethanol, C2H5OH,isthealcoholthatispresentinalcoholicdrinks.
(a) Ethanolissolubleinwater.Completethediagrambelowtoshowwhyethanolissolubleinwater.Youshouldincluderelevantlonepairsanddipolesandlabelthebondresponsibleforthissolubility. [3]
H5C2O
H
(b) Ifitissuspectedthatadriverhasbeendrinkingalcoholtheycanbetestedinseveralways.
(i) Onemethodpreviouslyusedtotestforethanolinbreathinvolvedblowingthroughacidified potassium dichromate(VI). A positive test was shown by the colourchangefromorangetogreen.
Whattypeofreactioncausesthiscolourchange? [1]
© WJEC CBAC Ltd.
PMT
(1092-01)
(ii) Anothermethod uses IR spectroscopy. The IR spectrum for ethanol is shownbelow.
Turn over.
15 Examineronly
0
50
100
4000 3000 2000 1500 1000 500
I State which functional group is shown to be present in ethanol by theabsorptionatabout3350cm–1. [1]
II A student suggested that this absorption should be used to test for thepresence of ethanol in breath. Give a reason why this suggestion is notvalid. [1]
(c) Ifethanol,inadrinksuchaswine,isleftinanopenbottleandexposedtoairitbecomes‘sour’andunpleasanttotaste.Thisisbecauseitformsethanoicacid.
(i) Draw the displayedformulaofethanoicacid. [1]
(ii) WhatsignificantchangewouldbenoticediftheIRspectrumofthisproductwascomparedwiththatofethanol?Givethereasonforthischange. [2]
Total[9]
Tran
smitt
ance
/%
Wavenumber/cm–1
© WJEC CBAC Ltd.
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Examineronly
12. TheelementsinGroup7inthePeriodicTablecanbedescribedasp-blockelements.
(a) Statewhythesearedescribedasp-blockelements. [1]
(b) Allhalogensareoxidisingagents.
(i) Whyarethehalogensoxidisingagents? [1]
(ii) State,givingareason,whichhalogenisthestrongestoxidisingagent. [1]
(c) NaClO3wasusedasaweedkiller.GivetheoxidationstateofchlorineinNaClO3.
Oxidation state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [1]
(d) Methane reactswith chlorinewhen exposed to sunlight. The first two stages of themechanismofthisreactionareinitiationandpropagation.
(i) Givetheequationfortheinitiationreaction. [1]
(ii) Give equations for two propagation steps involved in the formation ofchloromethane. [2]
© WJEC CBAC Ltd.
PMT
(1092-01)
(e) Chlorofluorocarbons,CFCs,werewidelyusedasrefrigerantsbuttheycausedseriousenvironmentaldamageasaresultofreactionsinvolvingradicalmechanisms.
Thefirststageofaradicalmechanismisaninitiationprocesssimilartothatin(d). Complete the following equation to show the most likely initiation step for
chlorofluoromethane,CH2ClF,andgiveareasonforyouranswer. [2]
17 Examineronly
F C H
Cl
H
Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total[9]
Total Section B [70]
© WJEC CBAC Ltd.
PMT
Questionnumber Write the question numbers in the left-hand margin
Examineronly
(1092-01)
18
© WJEC CBAC Ltd.
PMT
Examineronly
(1092-01) Turn over.
19
Questionnumber Write the question numbers in the left-hand margin
© WJEC CBAC Ltd.
PMT
Questionnumber Write the question numbers in the left-hand margin
Examineronly
(1092-01)
20
© WJEC CBAC Ltd.
PMT
SJJ*(S12-1092-01A)
GCE AS/A level
1092/01-A
CHEMISTRY – DATA SHEETFOR USE WITH CH2
P.M. WEDNESDAY, 23 May 2012
PMT
(1092-01A)
2
Infrared Spectroscopy characteristic absorption values
Bond Wavenumber / cm–1
500 to 600650 to 800
1000 to 13001620 to 16701650 to 17502100 to 22502800 to 31002500 to 35503300 to 3500
C—BrC—ClC—OC CC OC NC—HO—HN—H
——
———
——
PMT
(1092-01A)
3
TH
E P
ER
IOD
IC T
AB
LE
12
Gro
up3
45
67
0
1 2 3 4 5 6 7
6.94 Li
Lith
ium
3
9.01 Be
Bery
llium
4
10.8 B
Bor
on 5
12.0 C
Car
bon
6
14.0 N
Nitr
ogen
7
16.0 O
Oxy
gen
8
19.0 F
Fluo
rine
9
20.2
Ne
Neo
n10
23.0
Na
Sodi
um11
24.3
Mg
Magn
esium
12
27.0 Al
Alum
inium
13
28.1 Si
Silic
on14
31.0 P
Phosp
horus
15
32.1 S
Sulfu
r16
35.5 Cl
Chlo
rine
17
40.0
Ar
Arg
on18
39.1 K
Pota
ssium
19
40.1
Ca
Cal
cium
20
45.0 Sc
Scan
dium
21
47.9 Ti
Tita
nium
22
50.9 V
Vana
dium
23
52.0 Cr
Chro
mium
24
54.9
Mn
Man
gane
se25
55.8 Fe Iron 26
58.9
Co
Cob
alt
27
58.7 Ni
Nic
kel
28
63.5
Cu
Cop
per
29
65.4
Zn
Zin
c30
69.7
Ga
Gal
lium
31
72.6
Ge
Germ
anium
32
74.9 As
Ars
enic
33
79.0 Se
Selen
ium
34
79.9 Br
Brom
ine
35
83.8
Kr
Kry
pton
36
85.5
Rb
Rubid
ium37
87.6 Sr
Stro
ntium
38
88.9 Y
Ytt
rium
39
91.2 Zr
Zirco
nium
40
92.9
Nb
Nio
bium
41
95.9
Mo
Molyb
denum
42
98.9 Tc
Tech
netiu
m43
101
Ru
Ruthe
nium
44
103
Rh
Rhod
ium
45
106
PdPa
lladiu
m46
108
Ag
Silv
er47
112
Cd
Cadm
ium48
115 In
Indi
um49
119
Sn Tin 50
122
SbAn
timon
y51
128
TeTe
lluriu
m52
127 I
Iodi
ne53
131
Xe
Xen
on54
133
Cs
Caes
ium
55
137
Ba
Bar
ium
56
139
La
Lanth
anum
57
179
Hf
Haf
nium
72
181
TaTa
ntalu
m73
184 W
Tung
sten
74
186
Re
Rhen
ium
75
190
Os
Osm
ium
76
192 Ir
Irid
ium
77
195 Pt
Plat
inum
78
197
Au
Gol
d79
201
Hg
Mer
cury
80
204
Tl
Thal
lium
81
207
Pb Lea
d82
209 Bi
Bism
uth
83
(210
)Po
Polo
nium
84
(210
)A
tA
stat
ine
85
(222
)R
nR
adon
86
(223
)Fr
Fran
cium
87
(226
)R
aR
adiu
m88
(227
)A
cAc
tiniu
m89
‣ ‣‣
1.01 H
Hydr
ogen
1
4.00 He
Heliu
m2
d Bl
ock
s Blo
ckPe
riod
p Bl
ock
140
Ce
Cer
ium
58
141 Pr
Pras
eody
mium
59
144
Nd
Neo
dym
ium
60
(147
)Pm
Prom
ethi
um61
150
SmSa
mar
ium
62
(153
)Eu
Euro
pium
63
157
Gd
Gad
oliniu
m64
159
Tb
Terb
ium
65
163
Dy
Dys
pros
ium66
165
Ho
Hol
miu
m67
167
ErEr
bium
68
169
TmTh
uliu
m69
173
Yb
Ytter
bium
70
175
LuLu
tetiu
m71
232
Th
Thor
ium
90
(231
)Pa
Prot
actin
ium91
238 U
Ura
nium
92
(237
)N
pN
eptu
nium
93
(242
)Pu
Plut
oniu
m94
(243
)A
mA
mer
icium
95
(247
)C
mC
uriu
m96
(245
)Bk
Berk
elium
97
(251
)C
fCa
liforn
ium98
(254
)E
sEi
nstei
nium
99
(253
)Fm
Ferm
ium
100
(256
)M
dM
ende
leviu
m10
1
(254
)N
oN
obeli
um10
2
(257
)Lr
Lawr
enciu
m10
3
f Blo
ck
‣ Lan
than
oid
e
lem
ents
‣‣ A
ctin
oid
e
lem
ents
Ar
Sym
bol
Name Z
rela
tive
atom
icm
ass
atom
icnu
mbe
r
Key
PMT