Cambridge International Examinations Cambridge ... (0620)/0620_w18_q… · READ THESE INSTRUCTIONS...
Transcript of Cambridge International Examinations Cambridge ... (0620)/0620_w18_q… · READ THESE INSTRUCTIONS...
READ THESE INSTRUCTIONS FIRST
Write your Centre number, candidate number and name on all the work you hand in.
Write in dark blue or black pen.
You may use an HB pencil for any diagrams or graphs.
Do not use staples, paper clips, glue or correction fluid.DO NOT WRITE IN ANY BARCODES.
Answer all questions.
Electronic calculators may be used.
A copy of the Periodic Table is printed on page 16.
You may lose marks if you do not show your working or if you do not use appropriate units.
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part question.
CHEMISTRY 0620/42
Paper 4 Theory (Extended) October/November 2018
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.
Cambridge International Examinations
Cambridge International General Certificate of Secondary Education
This document consists of 13 printed pages and 3 blank pages.
[Turn overIB18 11_0620_42/3RP
© UCLES 2018
*4401701629*
The syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate.
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1 Element X can undergo the following physical changes.
gaseous Xboiling or
evaporation
liquid X
solid X
2
4
3
1
(a) (i) Givethescientificnameforeachofthenumberedphysicalchanges.
1 ..........................................................................................................................................
2 ..........................................................................................................................................
3 ..........................................................................................................................................
4 .......................................................................................................................................... [4]
(ii) Explain why the changes shown are physical changes.
.............................................................................................................................................
....................................................................................................................................... [1]
(iii) Onedifferencebetweenboilingandevaporationistherateatwhichtheprocessesoccur.
State oneotherdifferencebetweenboilingandevaporation.
.............................................................................................................................................
....................................................................................................................................... [1]
(b) Describetheseparation,arrangementandmotionofparticlesofelementX in the solid state.
separation ..................................................................................................................................
arrangement ..............................................................................................................................
motion ........................................................................................................................................ [3]
(c) Element XisaGroupImetal.ItburnsinairtoformanoxideX2O.
Write a chemical equation for this reaction.
.............................................................................................................................................. [2]
[Total: 11]
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2 Magnesium,calciumandstrontiumareGroupIIelements.
(a) Completethetabletoshowthearrangementofelectronsinacalciumatom.
shellnumber 1 2 3 4
numberofelectrons
[1]
(b) Describehowthearrangementofelectronsinastrontiumatomis:
(i) similar to the arrangement of electrons in a calcium atom
.............................................................................................................................................
.............................................................................................................................................
(ii) different from the arrangement of electrons in a calcium atom.
.............................................................................................................................................
.............................................................................................................................................
[2]
(c) Calcium reacts with cold water to form two products:
● acolourlessgas,P,which‘pops’withalightedsplint ● aweaklyalkalinesolution,Q,whichturnsmilkywhencarbondioxideisbubbledthroughit.
(i) Name gas P.
....................................................................................................................................... [1]
(ii) IdentifytheionresponsibleformakingsolutionQ alkaline.
....................................................................................................................................... [1]
(iii) Suggest the pH of solution Q.
....................................................................................................................................... [1]
(iv) Write a chemical equation for the reaction of calcium with cold water.
....................................................................................................................................... [2]
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(d) Magnesiumreactswithchlorinetoformmagnesiumchloride,MgCl 2. Magnesium chloride is
an ionic compound.
(i) Complete the diagrams to show the electronic structures of the ions in magnesium chloride.
Show the charges on the ions.
Cl
......
Mg
......
Cl
......
[3]
(ii) Give three physical properties that are typical of ionic compounds such as MgCl 2.
1 ..........................................................................................................................................
2 ..........................................................................................................................................
3 ..........................................................................................................................................
[3]
(e) Aqueous magnesium chloride is added to aqueous silver nitrate. A white precipitate forms.
Write an ionicequationforthisreaction.Includestatesymbols.
.............................................................................................................................................. [2]
[Total: 16]
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3 Sulfur is an important element.
(a) Explainhowburningfossilfuelscontainingsulfurleadstotheformationofacidrain.
....................................................................................................................................................
....................................................................................................................................................
.............................................................................................................................................. [2]
(b) SulfuricacidismanufacturedbytheContactprocess.OnestepintheContactprocessinvolvesareversiblereactioninwhichsulfurtrioxide,SO3,isformed.
(i) Writeachemicalequationforthisreversiblereaction.Includethecorrectsymboltoshowthatthereactionisreversible.
....................................................................................................................................... [2]
(ii) Statetheconditionsandnamethecatalystusedinthisreversiblereaction.
temperature ........................................................................................................................
pressure ..............................................................................................................................
catalyst ...............................................................................................................................
[3]
(iii) Describehowthesulfurtrioxideformedisconvertedintosulfuricacidinthenextstepsofthe Contact process.
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [2]
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(c) Dilute sulfuric acid is used to make salts known as sulfates.
Amethodconsistingofthreestepsisusedtomakezincsulfatefromzinccarbonate.
step 1 Addanexcessofzinccarbonateto20cm3of0.4mol/dm3 dilute sulfuric acid until
the reaction is complete.
step 2 Filter the mixture.
step 3 Heatthefiltrateuntilasaturatedsolutionformsandthenallowittocrystallise.
(i) Nameasuitablepieceofapparatusformeasuring20cm3 of dilute sulfuric acid in step 1.
....................................................................................................................................... [1]
(ii) State twoobservationswhichwouldshowthatthereactioniscompleteinstep 1.
1 ..........................................................................................................................................
2 ..........................................................................................................................................
[2]
(iii) Whyisitimportanttoaddanexcessofzinccarbonateinstep 1?
....................................................................................................................................... [1]
(iv) Whatismeantbythetermsaturated solution in step 3?
.............................................................................................................................................
....................................................................................................................................... [2]
(v) The equation for the reaction is shown.
ZnCO3(s) + H2SO4(aq) ZnSO4(......) + H2O(l) + CO2(g)
Completetheequationbyinsertingthestatesymbolforzincsulfate. [1]
(vi) Name another zinc compound which could be used to make zinc sulfate from dilutesulfuric acid using this method.
....................................................................................................................................... [1]
(vii) Suggest why this method would notworktomakebariumsulfatefrombariumcarbonateand dilute sulfuric acid.
....................................................................................................................................... [1]
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(d) In a titration, a student added 25.0cm3 of 0.200mol/dm3 aqueous sodium hydroxide to a
conical flask.The student thenaddeda fewdrops ofmethyl orange to the solution in theconicalflask.
Dilutesulfuricacidwasthenaddedfromaburettetotheconicalflask.Thevolumeofdilutesulfuricacidneededtoneutralisetheaqueoussodiumhydroxidewas20.0cm3.
2NaOH + H2SO4 Na2SO4 + 2H2O
(i) What was the colour of the methyl orange in the aqueous sodium hydroxide?
....................................................................................................................................... [1]
(ii) Determinetheconcentrationofthedilutesulfuricaciding/dm3.
● Calculate thenumberofmolesofaqueoussodiumhydroxideaddedto theconicalflask.
.............................. mol
● Calculatethenumberofmolesofdilutesulfuricacidaddedfromtheburette.
.............................. mol
● Calculatetheconcentrationofthedilutesulfuricacidinmol/dm3.
..............................mol/dm3
● Calculatetheconcentrationofthedilutesulfuricaciding/dm3.
..............................g/dm3
[4]
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(e) Iron(II) sulfate decomposes when heated strongly.
2FeSO4(s) Fe2O3(s) + SO2(g) + SO3(g)
15.20gofFeSO4(s)washeatedandformed4.80gofFe2O3(s).
[Mr,FeSO4=152;Mr,Fe2O3=160]
Calculate the percentage yield for this reaction.
.............................. % [3]
[Total: 26]
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4 Astudentinvestigatedtheprogressofthereactionbetweendilutehydrochloricacid,HCl,andanexcessoflargepiecesofmarble,CaCO3,usingtheapparatusshown.
gas syringe
dilute
hydrochloric acid an excess of large
pieces of marble
(a) A graph of the volume of gas produced against time is shown.
150
100
50
0
volume of gas
produced / cm3
0 30 60 90 120
time / s
150 180 210 240
(i) How does the shape of the graph show that the rate of reaction decreased as the reaction
progressed?
.............................................................................................................................................
....................................................................................................................................... [1]
(ii) Why did the rate of reaction decrease as the reaction progressed?
....................................................................................................................................... [1]
(iii) Afterhowmanysecondsdidthereactionfinish?
.............................. s [1]
(b) Theexperimentwas repeatedusing the samemassof smaller piecesofmarble.All otherconditions were kept the same.
Draw a graph on the grid to show the progress of the reaction using the smaller pieces of
marble. [2]
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(c) The original experiment was repeated at a higher temperature. All other conditions were kept
the same.
Describeandexplain, in termsof collisionsbetweenparticles, theeffect of usingahighertemperatureonthetimetakenforthereactiontofinish.
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
..............................................................................................................................................[5]
[Total:10]
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5 Alkynesareahomologousseriesofunsaturatedhydrocarbons. AllmemberscontainaC≡Ctriplebond.
(a) Completethetableshowinginformationaboutthefirstthree alkynes.
formula C2H2 C3H4
structure H–C≡C–H H–C≡C–CH3 H–C≡C–CH2–CH3
name ethyne butyne
[2]
(b) Completethedot-and-crossdiagramtoshowtheelectronarrangementinamoleculeofethyne, H–C≡C–H.Showoutershellelectronsonly.
H HC C
[2]
(c) Compounds in the same homologous series have the same general formula.
(i) Give twoothercharacteristicsofmembersofahomologousseries.
1 ..........................................................................................................................................
2 ..........................................................................................................................................
[2]
(ii) Usetheinformationinthetablein(a) to deduce the general formula of alkynes.
....................................................................................................................................... [1]
(d) Alkynes are unsaturated.
Describeatestforunsaturation.
test .............................................................................................................................................
result ..........................................................................................................................................
[2]
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(e) (i) Nameanoxidisingagentwhichcanbeusedtooxidiseethanoltoethanoicacid.
....................................................................................................................................... [2]
(ii) Drawthestructureofethanoicacid.Showalloftheatomsandallofthebonds.
[1]
(f) Carboxylicacidscanbeconvertedintoesters.
(i) Theester formedby reactingpropanoicacidandmethanol has themolecular formulaC4H8O2.
Namethisesteranddrawitsstructure.Showalloftheatomsandallofthebonds.
name of the ester ................................................................................................................
structure of the ester
[2]
(ii) Name another ester with the molecular formula C4H8O2.
....................................................................................................................................... [1]
(g) Polyesters are polymers.
(i) What type of polymerisation is used in the manufacture of polyesters?
....................................................................................................................................... [1]
(ii) Name a polyester.
....................................................................................................................................... [1]
[Total: 17]
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BLANK PAGE
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Gro
up
Th
e P
eri
od
ic T
ab
le o
f E
lem
en
ts
1 Hh
yd
rog
en
1
2
He
he
lium
4
III
III
IVV
VI
VII
VII
I
3 Li
lith
ium
7
4 Be
be
rylli
um
9
ato
mic
nu
mb
er
ato
mic
sym
bo
l
Ke
y
na
me
rela
tive
ato
mic
ma
ss
11
Na
so
diu
m
23
12
Mg
ma
gn
esiu
m
24
19 K
po
tassiu
m
39
20
Ca
ca
lciu
m
40
37
Rb
rub
idiu
m
85
38
Sr
str
on
tiu
m
88
55
Cs
ca
esiu
m
13
3
56
Ba
ba
riu
m
13
7
87
Fr
fra
nciu
m
–
88
Ra
rad
ium
–
5 Bb
oro
n
11
13
Al
alu
min
ium
27
31
Ga
gallium
70
49
In
indium
115
81 Tl
thallium
204
6 Ccarbon
12
14 Si
silicon
28
32
Ge
germanium
73
50
Sntin
119
82
Pb
lead
207
22 Ti
titanium
48
40
Zr
zirconium
91
72
Hf
hafnium
178
104
Rf
rutherfordium
–
23 V
vanadium
51
41
Nb
niobium
93
73
Ta
tantalum
181
105
Db
dubnium
–
24
Cr
chromium
52
42
Mo
molybdenum
96
74
Wtungsten
184
106
Sg
seaborgium
–
25
Mn
manganese
55
43
Tc
technetium
– 75
Re
rhenium
186
107
Bh
bohrium
–
26
Fe
iron
56
44
Ru
ruthenium
101
76
Os
osmium
190
108
Hs
hassium
–
27
Co
cobalt
59
45
Rh
rhodium
103
77
Ir
iridium
192
109
Mt
meitnerium
–
28
Ni
nickel
59
46
Pd
palladium
106
78
Pt
platinum
195
110
Ds
darmstadtium
–
29
Cu
copper
64
47
Ag
silver
108
79
Au
gold
197
111
Rg
roentgenium
–
30
Zn
zinc
65
48
Cd
cadmium
112
80
Hg
mercury
201
112
Cn
copernicium
–
114
Fl
flerovium
–
116
Lv
livermorium
–
7 Nnitrogen
14
15 P
phosphorus
31
33
As
arsenic
75
51
Sb
antimony
122
83 Bi
bismuth
209
8 Ooxygen
16
16 S
sulfur
32
34
Se
selenium
79
52
Te
tellurium
128
84
Po
po
lon
ium
–
9 Fflu
orin
e
19
17
Cl
ch
lorin
e
35
.5
35
Br
bro
min
e
80
53 I
iod
ine
12
7
85
At
asta
tin
e
–
10
Ne
ne
on
20
18
Ar
arg
on
40
36
Kr
kry
pto
n
84
54
Xe
xe
no
n
13
1
86
Rn
rad
on
–
21
Sc
sca
nd
ium
45
39 Y
ytt
riu
m
89
57
–7
1
lan
tha
no
ids
89
–1
03
actin
oid
s
57
La
lan
tha
nu
m
13
9
89
Ac
lan
tha
no
ids
actin
oid
s
Th
e v
olu
me
of
on
e m
ole
of
an
y g
as is 2
4 d
m3 a
t ro
om
te
mp
era
ture
an
d p
ressu
re (
r.t.
p.)
.
actin
ium
–
58
Ce
ce
riu
m
140
90
Th
thorium
232
59
Pr
praseodymium
141
91
Pa
protactinium
231
60
Nd
neodymium
144
92 U
uranium
238
61
Pm
promethium
– 93
Np
neptunium
–
62
Sm
samarium
150
94
Pu
plutonium
–
63
Eu
europium
152
95
Am
americium
–
64
Gd
gadolinium
157
96
Cm
curium
–
65
Tb
terbium
159
97
Bk
berkelium
–
66
Dy
dysprosium
163
98
Cf
californium
–
67
Ho
holmium
165
99
Es
einsteinium
–
68
Er
erbium
167
100
Fm
fermium
–
69
Tm
thulium
169
101
Md
mendelevium
–
70
Yb
ytterbium
173
102
No
nobelium
–
71
Lu
lutetium
175
103
Lr
lawrencium
–