November 2015 (v1) QP - Paper 3 CIE Chemistry IGCSE
November 2015 (v1) QP - Paper 3 CIE Chemistry IGCSE
November 2015 (v1) QP - Paper 3 CIE Chemistry IGCSE
CHEMISTRY 0620/31
Paper 3 (Extended) October/November 2015
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.
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.
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.
The syllabus is approved for use in England, Wales and Northern Ireland as a Cambridge International Level 1/Level 2 Certificate.
IB15 11_0620_31/3RP
© UCLES 2015 [Turn over
PMT
Select from the list of particles to answer the following questions. A particle may be selected
once, more than once or not at all.
(i) Which two ions have the same electronic structure? ................................................... [1]
(ii) Which ion has the same electronic structure as an atom of argon? ............................. [1]
(iii) Which atom can form an ion of the type X3–? ............................................................... [1]
(iv) Which atom can form a hydride which has a formula of the type XH4? ........................ [1]
64
(b) (i) How many protons, neutrons and electrons are there in one copper(II) ion 29 Cu 2+ ?
How many nucleons and how many charged particles are there in one atom of scandium?
23 24
(c) Two different atoms of sodium are 11 Na and 11 Na .
.............................................................................................................................................
....................................................................................................................................... [2]
24
(ii) 11Na is radioactive. It changes into an atom of a different element which has one more
proton.
....................................................................................................................................... [1]
.............................................................................................................................................
....................................................................................................................................... [2]
[Total: 13]
2 Describe how to separate the following. In each example, give a description of the procedure used
and explain why this method works.
(a) Copper powder from a mixture containing copper and zinc powders.
procedure ..................................................................................................................................
....................................................................................................................................................
explanation ................................................................................................................................
....................................................................................................................................................
[3]
procedure ..................................................................................................................................
....................................................................................................................................................
explanation ................................................................................................................................
....................................................................................................................................................
[3]
(c) Glycine from a mixture of the two amino acids glycine and alanine. Glycine has the lower Rf
value.
procedure ..................................................................................................................................
....................................................................................................................................................
explanation ................................................................................................................................
....................................................................................................................................................
[2]
(d) Magnesium hydroxide from a mixture of magnesium hydroxide and zinc hydroxide.
procedure ..................................................................................................................................
....................................................................................................................................................
explanation ................................................................................................................................
....................................................................................................................................................
[3]
[Total: 11]
....................................................................................................................................................
.............................................................................................................................................. [2]
(b) The following equation represents the equilibrium in the Contact process.
....................................................................................................................................................
.............................................................................................................................................. [2]
(d) The forward reaction is exothermic. The reaction is usually carried out at a temperature between
400 and 450 °C.
(i) What is the effect on the position of equilibrium of using a temperature above 450 °C?
Explain your answer.
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [2]
(ii) What is the effect on the rate of using a temperature below 400 °C?
Explain your answer.
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [3]
(e) A low pressure, 2 atmospheres, is used. At equilibrium, about 98% SO3 is present.
(i) What is the effect on the position of equilibrium of using a higher pressure?
....................................................................................................................................... [1]
....................................................................................................................................... [1]
.............................................................................................................................................. [1]
(g) Describe how concentrated sulfuric acid is made from sulfur trioxide.
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
.............................................................................................................................................. [2]
[Total: 15]
(i) Describe two problems caused by the disposal of synthetic polymers in landfill sites.
.............................................................................................................................................
....................................................................................................................................... [2]
....................................................................................................................................... [1]
....................................................................................................................................................
.............................................................................................................................................. [1]
(c) The structural formulae of two synthetic polymers are given below.
CH2 CH CH2 CH
polymer A
CH3 CH3
O O O O
polymer B
C C O O C C O O
[2]
....................................................................................................................................... [1]
(iii) Deduce the two types of organic compound which have reacted to form polymer B.
....................................................................................................................................... [2]
(d) Explain the difference between addition and condensation polymers. Classify A and B as
either addition or condensation polymers.
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
.............................................................................................................................................. [3]
[Total: 12]
5 (a) A compound, X, contains 55.85% carbon, 6.97% hydrogen and 37.18% oxygen.
(i) How does this prove that compound X contains only carbon, hydrogen and oxygen?
....................................................................................................................................... [1]
(ii) Use the above percentages to calculate the empirical formula of compound X.
....................................................................................................................................... [2]
....................................................................................................................................... [2]
(b) (i) Bromine water changes from brown to colourless when added to X.
....................................................................................................................................... [1]
....................................................................................................................................... [1]
[1]
[Total: 8]
6 Carbon and silicon are elements in Group IV. They both form oxides of the type XO2.
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [3]
(ii) State three properties which silicon(IV) oxide and diamond have in common.
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [3]
(iii) How could you show that silicon(IV) oxide is acidic and not basic or amphoteric?
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [2]
(b) Explain why the physical properties of carbon dioxide are different from those of diamond and
silicon(IV) oxide.
....................................................................................................................................................
.............................................................................................................................................. [1]
[Total: 9]
10
(a) The decomposition of silver bromide is the basis of film photography. This is a redox reaction.
step 2 Ag+ + e– → Ag
....................................................................................................................................... [1]
....................................................................................................................................... [1]
(b) A piece of white paper was coated with silver bromide and exposed to the light. Sections of the
paper were covered as shown in the diagram.
not covered
covered with
thin paper
covered with
thick card
Predict the appearance of the different sections of the paper after exposure to the light and the
removal of the card. Explain your predictions.
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
.............................................................................................................................................. [4]
11
(c) Photosynthesis is another example of a photochemical reaction. Green plants can make simple
carbohydrates, such as glucose. These can polymerise to make more complex carbohydrates,
such as starch.
....................................................................................................................................... [2]
(ii) Name the substance which is responsible for the colour in green plants and is essential for
photosynthesis.
....................................................................................................................................... [1]
Draw part of the structural formula of starch which contains two glucose units.
[2]
....................................................................................................................................... [1]
[Total: 12]
7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10
23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18
39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
12
85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
0620/31/O/N/15
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
133 137 139 178 181 184 186 190 192 195 197 201 204 207 209
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Caesium Barium Lanthanum Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon
55 56 57 * 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
226 227
Fr Ra Ac
Francium Radium Actinium
87 88 89
140 141 144 150 152 157 159 162 165 167 169 173 175
*58-71 Lanthanoid series
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
90-103 Actinoid series Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium
58 59 60 61 62 63 64 65 66 67 68 69 70 71
a a = relative atomic mass 232 238
Key X X = atomic symbol Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium
b b = proton (atomic) number 90 91 92 93 94 95 96 97 98 99 100 101 102 103
The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).
Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after
To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International
PMT