0620/42 october/november 2016 · chemistry 0620/42 paper 4 theory (extended) october/november 2016...
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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 2016
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.
Cambridge International ExaminationsCambridge International General Certificate of Secondary Education
This document consists of 15 printed pages and 1 blank page.
[Turn overIB16 11_0620_42/4RP© UCLES 2016
*5182765417*
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 Particles behave differently when in different physical states.
(a) Solids have a fixed volume and a definite shape. Gases have no fixed volume and take the shape of the container.
Describe the volume and shape of liquids.
....................................................................................................................................................
.............................................................................................................................................. [1]
(b) Complete the table to show the separation, arrangement and movement of particles in eachphysical state.
state separation of particles arrangement of particles movement of particles
solid
liquid touching one another randomly arranged move over one another
gas
[6]
(c) Name the following changes of state.
(i) Ice turning into water.
....................................................................................................................................... [1]
(ii) Solid carbon dioxide turning directly into gaseous carbon dioxide at room temperature.
....................................................................................................................................... [1]
[Total: 9]
Liquids have a fixed volume and take the shape of the container in which they are poured
touching regular vibrate
not touchng random random
Sublimation
Melting
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2 This question is about atoms, ions and isotopes.
(a) Define the term nucleon number.
....................................................................................................................................................
.............................................................................................................................................. [2]
(b) Give the electronic structure of the following atom and ion.
Na ..............................................................................................................................................
P3– ..............................................................................................................................................[2]
(c) State one medical use of radioactive isotopes.
.............................................................................................................................................. [1]
(d) What is meant by the term relative atomic mass?
[2]
(e) Suggest why the relative atomic mass of chlorine is not a whole number.
[2]
The total number of protons and neutrons in the nucleus of an atom is called as the nucleon number
2:8:12:8:8
In the treatment of cancer
Relative atomic mass is the average mass of naturally occuring atoms of an element on a scale where the mass of Carbon-12 is exactly 12 units
Chlorine must have more than one isotope and the masses of these isotopes are averaged . Hence the relative atomic mass of chlorine is not a whole number.
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(f) Aluminium is a metal in Group III.
Describe the bonding in aluminium. Include a labelled diagram and any appropriate charges in your answer.
[3]
[Total: 12]
Aluminium consists of a lattice of Al3+ ions with electrons between the ions .There exists attraction between the positive ions and the sea of delocalised electrons
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3 Clean, dry air contains a small amount of carbon dioxide.
(a) The percentages of the other gases present in clean, dry air are shown in the table.
Complete the table by inserting the names of these gases.
name of gas percentage present
78
21
1[2]
(b) Oxides of nitrogen are atmospheric pollutants which can cause acid rain.
Describe the formation of oxides of nitrogen and suggest how they can cause acid rain.
[3]
(c) Methane contributes to the greenhouse effect.
State two sources of methane.
1 Animal waste
2 Fractional distillation of petroleum[2]
(d) Combustion and respiration add carbon dioxide to the atmosphere.
Name one natural process which removes carbon dioxide from the atmosphere.
[1]
[Total: 8]
nitrogenoxygennoble gases
Nitrogen and oxygen from the air react in the high temperatures of a car engine to form oxides of nitrogen . These then dissolve in water to form an acid.
Photosynthesis
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4 Dilute nitric acid behaves as a typical acid in some reactions but not in other reactions.
(a) Dilute nitric acid behaves as a typical acid when reacted with copper(II) oxide and withcopper(II) carbonate.
Describe what you would see if excess dilute nitric acid is added separately to solid samplesof copper(II) carbonate and copper(II) oxide followed by warming the mixtures.
copper(II) carbonate
copper(II) oxide
[4]
(b) When dilute nitric acid is added to pieces of copper and heated, a reaction takes place andcopper(II) nitrate is formed.
(i) Part of the chemical equation for the reaction between copper and dilute nitric acid isshown.
Complete the chemical equation by inserting the formula of copper(II) nitrate and balancingthe equation.
3Cu(s) + 8HNO3(aq) → 3Cu(NO3)2(aq) + 4H2O(l) + 2NO(g)[2]
(ii) How is the reaction of dilute nitric acid with copper different from that of a typical metal witha typical acid?
Hydrogen gas is not produced when copper reacts with nitric acid)
[Total: 7]
The bubbles disappear
It dissolves and forms a blue solution
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5 Chlorine, bromine and iodine are halogens.
(a) Chlorine can be made in the laboratory by heating manganese(IV) oxide with concentratedhydrochloric acid.
MnO2(s) + 4HCl (aq) → MnCl 2(aq) + 2H2O(l) + Cl 2(g)
Calculate the volume of 8.00 mol / dm3 HCl (aq) needed to react with 3.48 g of MnO2.
• moles of MnO2 used
• moles of HCl needed
................................ mol• volume of HCl needed
................................ cm3
[4]
(b) A student bubbled chlorine gas into a test-tube containing aqueous potassium bromide.
(i) Describe the colour change seen in the test-tube.
from ............................................................... to ...............................................................[2]
(ii) Complete the ionic equation for this reaction.
Include state symbols.
Cl 2(g) + ......Br –(aq) → ................ + ................[3]
Moles of MnO2 =Mass/Mr=3.48/87=0.04
*Moles of HCl needed= 4 xMoles of MnO2= 0.04*4=0.16
(0.16/8) x 1000 =20cm3
courless yellow/orange /brown
2 Br2(aq) + 2Cl –(aq)
*FromStoichiometry of the equation
0.16
20
Moles of HCl = 4 x Moles of 4
Volume = moles/concentration= 0.16/8=0.02dm3
=0.02 x 1000=20cm3
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(c) When one mole of bromine, Br2, reacts with one mole of propene, one organic product isformed.
(i) Which part of the propene molecule reacts with bromine?
[1]
(ii) What is the name of the type of reaction which takes place between bromine and propene?
[1]
(d) When one mole of chlorine, Cl 2, reacts with one mole of propane, a mixture of two structuralisomers is formed.
(i) What is the name of the type of reaction which takes place between chlorine and propane?
[1]
(ii) Explain what is meant by the term structural isomers.
[2]
(iii) Draw the structure of two structural isomers formed when one mole of chlorine reacts with
one mole of propane.
[2]
Bromination
Substitution
Compounds with the same molecular formula but different structural formulae are called structural isomers
The C=C double bond
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(e) Iodine forms an oxide which has the composition by mass: I, 76.0%; O, 24.0%.
(i) Use this information to determine the empirical formula of this oxide of iodine.
empirical formula ...I2O5. [3]
(ii) The oxide of iodine in (e)(i) dissolves in water.
Predict and explain the effect of adding Universal Indicator to an aqueous solution of thisoxide of iodine.
effect on Universal Indicator : Turns pinkexplanation .: This is because iodine is a non metal
[2]
[Total: 21]
Moles of Iodine = 76.0 / 127 =0.59 Mole
Hence
I O
1*2=2 2.5*2=5
Moles of oxygen =24.0 / 16.0 =1.5 Mole
Mole ratio 1 : 2.5
Thus making the respective moles as their subscripts we get the following formula
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6 Aluminium is a very important metal.
Aluminium is extracted from its ore, bauxite, by electrolysis. Bauxite is an impure form of aluminium oxide, Al 2O3.
(a) Describe how aluminium is extracted from bauxite. Include an ionic half-equation for thereaction at each electrode.
description
ionic half-equation for the anode reaction
ionic half-equation for the cathode reaction .[5]
(b) Explain why the anodes have to be replaced regularly.
[2]
(c) Give two uses of aluminium and give a reason why aluminium is suitable for each use.
[4]
[Total: 11]
Bauxite is dissolved in molten cryolite. This is because cryolite lowers the melting temperature. Molten aluminium forms at the cathode and Oxygen gas forms at the anode.
2O2– → O2 + 4e–Al3+ + 3e– → Al
Carbon electrodes burn in oxygen hence need to be replaced
Use 1:manufacture of aircraft
Reason 1:low density
Use 2: food containers OR cooking foil
reason 2: Al resistant to corrosionwww.sm
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Question 7 starts on the next page.
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7 Proteins are a major constituent of food.
Proteins are polymers.
(a) What is a polymer?
[2]
(b) Proteins can be converted into amino acids.
(i) Name the type of chemical reaction which occurs when proteins are converted into aminoacids.
[1]
(ii) Suggest a condition needed to convert proteins into amino acids.
[1]
(c) A colourless mixture of amino acids was separated by chromatography. Amino acid X has an Rf value of 0.8. The chromatogram of the mixture after treatment with a locating agent is shown.
solvent front
baseline
(i) How is an Rf value calculated?
Rf =[1]
(ii) On the diagram put a ring around the spot caused by amino acid X. [1]
Polymers are large molecules made from many monomers joinedtogether.
hydrolysis
acid conditions
distance moved by substance/distance moved by solvent frontwww.smart
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(iii) Describe how you would perform a chromatography experiment to produce thechromatogram shown in (c). Assume you have been given the mixture of amino acids anda suitable locating agent. You are provided with common laboratory apparatus.
[3]
A mixture of amino acids is placed as a spot onto a (pencil) baseline . The paper is then placed into a suitable solvent.After 10-15 minutes when the experiment gets done ( you cant see the spots yet but you can notice the solvent having moved up),add the locating agent added to the finished chromatogram to reveal spots.
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(d) When one molecule of an amino acid A combines with one molecule of another amino acid B,two different dipeptide molecules could be formed.
Draw the structures of the two different dipeptide molecules. Show all of the atoms and all of the bonds in the linkages.
amino acid A amino acid B
N
H
H
C
O
O H
O
O H
N
H
H
C
[3]
[Total: 12]
N
H
C
O
N
H
C
O
+ H2O
+ H2O
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To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series.
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Gro
up
The
Perio
dic
Tabl
e of
Ele
men
ts
1 Hhy
drog
en1
2 He
heliu
m4
III
IIIIV
VV
IV
IIV
III
3 Lilit
hium 7
4 Be
bery
llium
9
atom
ic n
umbe
r
atom
ic s
ymbo
l
Key
nam
ere
lativ
e at
omic
mas
s
11 Na
sodi
um23
12 Mg
mag
nesi
um24
19 Kpo
tass
ium
39
20 Ca
calc
ium
40
37 Rb
rubi
dium
85
38 Sr
stro
ntiu
m88
55 Cs
caes
ium
133
56 Ba
bariu
m13
7
87 Frfra
nciu
m–
88 Ra
radi
um –
5 B boro
n11 13 Al
alum
iniu
m27 31 Ga
galli
um70 49 In indi
um11
5
81 Tlth
alliu
m20
4
6 Cca
rbon
12 14 Si
silic
on28 32 Ge
germ
aniu
m73 50 Sn tin 119
82 Pb
lead
207
22 Titit
aniu
m48 40 Zr
zirc
oniu
m91 72 Hf
hafn
ium
178
104
Rf
ruth
erfo
rdiu
m–
23 Vva
nadi
um51 41 Nb
niob
ium
93 73 Tata
ntal
um18
1
105
Db
dubn
ium
–
24 Cr
chro
miu
m52 42 Mo
mol
ybde
num
96 74 Wtu
ngst
en18
4
106
Sg
seab
orgi
um–
25 Mn
man
gane
se55 43 Tc
tech
netiu
m– 75 Re
rhen
ium
186
107
Bh
bohr
ium
–
26 Fe iron
56 44 Ru
ruth
eniu
m10
1
76 Os
osm
ium
190
108
Hs
hass
ium
–
27 Co
coba
lt59 45 Rh
rhod
ium
103
77 Iriri
dium
192
109
Mt
mei
tner
ium
–
28 Ni
nick
el59 46 Pd
palla
dium
106
78 Pt
plat
inum
195
110
Ds
darm
stad
tium
–
29 Cu
copp
er64 47 Ag
silv
er10
8
79 Au
gold
197
111
Rg
roen
tgen
ium
–
30 Zn zinc 65 48 Cd
cadm
ium
112
80 Hg
mer
cury
201
112
Cn
cope
rnic
ium
–
114 Fl
flero
vium
–
116
Lvliv
erm
oriu
m–
7 Nni
troge
n14 15 P
phos
phor
us31 33 As
arse
nic
75 51 Sb
antim
ony
122
83 Bi
bism
uth
209
8 Oox
ygen
16 16 S sulfu
r32 34 Se
sele
nium
79 52 Tete
lluriu
m12
8
84 Po
polo
nium
–
9 Fflu
orin
e19 17 Cl
chlo
rine
35.5
35 Br
brom
ine
80 53 Iio
dine
127
85 At
asta
tine
–
10 Ne
neon 20 18 Ar
argo
n40 36 Kr
kryp
ton
84 54 Xe
xeno
n13
1
86 Rn
rado
n–
21 Sc
scan
dium
45 39 Yyt
trium 89
57–7
1la
ntha
noid
s
89–1
03ac
tinoi
ds
57 Lala
ntha
num
139
89 Ac
lant
hano
ids
actin
oids
The
volu
me
of o
ne m
ole
of a
ny g
as is
24
dm3 a
t roo
m te
mpe
ratu
re a
nd p
ress
ure
(r.t.p
.).
actin
ium
–
58 Ce
ceriu
m14
0
90 Th thor
ium
232
59 Pr
pras
eody
miu
m14
1
91 Pa
prot
actin
ium
231
60 Nd
neod
ymiu
m14
4
92 Uur
aniu
m23
8
61 Pm
prom
ethi
um– 93 Np
nept
uniu
m–
62 Sm
sam
ariu
m15
0
94 Pu
plut
oniu
m–
63 Eu
euro
pium
152
95 Am
amer
iciu
m–
64 Gd
gado
liniu
m15
7
96 Cm
curiu
m–
65 Tb terb
ium
159
97 Bk
berk
eliu
m–
66 Dy
dysp
rosi
um16
3
98 Cf
calif
orni
um–
67 Ho
holm
ium
165
99 Es
eins
tein
ium
–
68 Er
erbi
um16
7
100
Fm ferm
ium
–
69 Tm thul
ium
169
101
Md
men
dele
vium
–
70 Yb
ytte
rbiu
m17
3
102
No
nobe
lium
–
71 Lu lute
tium
175
103 Lr
law
renc
ium
–
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