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Practice paper written from an analysis of every
O-Level Science (Chemistry) paper, 2010–2026
Paper 1 Multiple Choice (Chemistry section)
FORECAST PAPER · SET 7 Medium
For practice before the 2026 examination
30 minutes
Additional Materials: Paper for your answers, numbered 1 to 20
Write in soft pencil.
Do not use staples, paper clips, glue or correction fluid.
There are twenty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D.
Choose the one you consider correct and record your choice on a separate sheet of paper, numbered 1 to 20.
Each correct answer will score one mark. A mark will not be deducted for a wrong answer.
Any rough working should be done in this booklet.
A copy of the Data Sheet is printed on page 9.
A copy of the Periodic Table is printed on page 10.
The use of an approved scientific calculator is expected, where appropriate.
Sea sand contains sodium chloride, which can damage the steel inside concrete.
A builder wants to separate a sample of sea sand into sand and crystals of sodium chloride.
Which method is suitable?
Silicon is the main material used in computer chips.
An atom of silicon has proton number 14 and nucleon number 28.
Which statement about this atom is correct?
Gallium compounds are used in light-emitting diodes (LEDs).
Two isotopes of gallium have nucleon numbers 69 and 71.
An ion of the heavier isotope has a charge of 3+ and 28 electrons.
How many neutrons are in this ion?
Bricks of magnesium oxide are used to line furnaces.
A brick of magnesium oxide, which has a giant ionic lattice, is hard but shatters when it is struck with a hammer.
Which statement explains why it shatters?
Silane, SiH4, is a covalent gas used to make silicon for computer chips.
Four statements about a molecule of silane are listed.
Which statements are correct?
Copper is removed from a circuit board by etching it with aqueous iron(III) chloride.
Which statement about this reaction is correct?
Limestone, CaCO3, is heated in a kiln to make quicklime, which is used in mortar.
100 g of calcium carbonate is heated until it has all reacted.
What is the mass of calcium oxide formed?
Which row describes an alkali?
| ion produced in aqueous solution | colour of Universal Indicator | |
|---|---|---|
| A | H+ | red or orange |
| B | H+ | blue or purple |
| C | OH− | red or orange |
| D | OH− | blue or purple |
Ammonium chloride is used in the flux that cleans metal surfaces for soldering.
A technician warms ammonium chloride with aqueous sodium hydroxide, a base.
Which gas is given off, and how is it identified?
Dilute hydrochloric acid is used to remove rust from steel girders.
Aqueous sodium hydroxide is added to a sample of the solution formed, until it is in excess.
A red-brown precipitate forms that does not dissolve.
Which ion is present in the solution?
A technician tests a solution, Y, that is used to clean circuit boards.
Separate samples of Y are added to two reagents.
| reagent | observation |
|---|---|
| aqueous potassium iodide | colourless solution turns brown |
| acidified aqueous potassium manganate(VII) | purple colour does not change |
What do the results show about Y?
Which graph shows how non-metallic character changes across Period 3 from sodium to chlorine?
Chlorine gas is bubbled through aqueous potassium bromide.
Which row describes the observation and the reason for it?
| observation | chlorine compared with bromine | |
|---|---|---|
| A | solution stays colourless | less reactive |
| B | solution stays colourless | more reactive |
| C | solution turns red-brown | less reactive |
| D | solution turns red-brown | more reactive |
A strip of one metal is added to an aqueous solution of the nitrate of another metal.
A metal reacts only if it is more reactive than the metal in the solution.
The letters are not the chemical symbols.
| metal added | solution | observation |
|---|---|---|
| W | Z nitrate | reaction |
| Y | W nitrate | reaction |
| Z | Y nitrate | no reaction |
| X | W nitrate | no reaction |
| Z | X nitrate | reaction |
What is the order of reactivity, from the most reactive metal to the least reactive metal?
A technician tests four solids, W, X, Y and Z, for use as additives in concrete.
In each test 5.0 g of the solid is stirred into 50 cm3 of water in a polystyrene cup.
| solid | initial temperature / °C | final temperature / °C |
|---|---|---|
| W | 29.0 | 25.5 |
| X | 19.0 | 23.0 |
| Y | 24.0 | 24.0 |
| Z | 27.0 | 31.0 |
Which statement is correct?
Diesel, the fuel for many construction machines, is obtained from crude oil.
Four statements about energy sources are listed.
Which two statements are correct?
Chloromethane, CH3Cl, is used to make the silicone sealant for window frames.
It is made when methane reacts with chlorine in ultraviolet light.
Which row shows X and the type of reaction?
| X | type of reaction | |
|---|---|---|
| A | hydrogen | addition |
| B | hydrogen | substitution |
| C | hydrogen chloride | addition |
| D | hydrogen chloride | substitution |
Which diagram shows part of the carbon chain of a molecule of a polyunsaturated fat?
Compound X is used to preserve stored grain. The displayed formula of X is shown.
Which statement about X is correct?
Waste poly(ethene) from the insulation on electrical cables is recycled in two ways.
In method 1, the waste is melted and made into pellets.
In method 2, the waste is cracked to make fuel.
Which statement is correct?
| aluminium hydroxide | white |
| calcium hydroxide | white |
| copper(II) hydroxide | light blue |
| iron(II) hydroxide | green |
| iron(III) hydroxide | red-brown |
| zinc hydroxide | white |
Group | |||||||||||||||||
1 | 2 |
| 13 | 14 | 15 | 16 | 17 | 18 | |||||||||
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| 1 H hydrogen 1 |
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| 2 He helium 4 | ||
3 Li lithium 7 | 4 Be beryllium 9 |
| proton (atomic) number atomic symbol name relative atomic mass |
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| 5 B boron 11 | 6 C carbon 12 | 7 N nitrogen 14 | 8 O oxygen 16 | 9 F fluorine 19 | 10 Ne neon 20 | ||
11 Na sodium 23 | 12 Mg magnesium 24 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 Al aluminium 27 | 14 Si silicon 28 | 15 P phosphorus 31 | 16 S sulfur 32 | 17 Cl chlorine 35.5 | 18 Ar argon 40 |
19 K potassium 39 | 20 Ca calcium 40 | 21 Sc scandium 45 | 22 Ti titanium 48 | 23 V vanadium 51 | 24 Cr chromium 52 | 25 Mn manganese 55 | 26 Fe iron 56 | 27 Co cobalt 59 | 28 Ni nickel 59 | 29 Cu copper 64 | 30 Zn zinc 65 | 31 Ga gallium 70 | 32 Ge germanium 73 | 33 As arsenic 75 | 34 Se selenium 79 | 35 Br bromine 80 | 36 Kr krypton 84 |
37 Rb rubidium 85 | 38 Sr strontium 88 | 39 Y yttrium 89 | 40 Zr zirconium 91 | 41 Nb niobium 93 | 42 Mo molybdenum 96 | 43 Tc technetium – | 44 Ru ruthenium 101 | 45 Rh rhodium 103 | 46 Pd palladium 106 | 47 Ag silver 108 | 48 Cd cadmium 112 | 49 In indium 115 | 50 Sn tin 119 | 51 Sb antimony 122 | 52 Te tellurium 128 | 53 I iodine 127 | 54 Xe xenon 131 |
55 Cs caesium 133 | 56 Ba barium 137 | 57–71 lanthanoids
| 72 Hf hafnium 178 | 73 Ta tantalum 181 | 74 W tungsten 184 | 75 Re rhenium 186 | 76 Os osmium 190 | 77 Ir iridium 192 | 78 Pt platinum 195 | 79 Au gold 197 | 80 Hg mercury 201 | 81 Tl thallium 204 | 82 Pb lead 207 | 83 Bi bismuth 209 | 84 Po polonium – | 85 At astatine – | 86 Rn radon – |
87 Fr francium – | 88 Ra radium – | 89–103 actinoids
| 104 Rf rutherfordium – | 105 Db dubnium – | 106 Sg seaborgium – | 107 Bh bohrium – | 108 Hs hassium – | 109 Mt meitnerium – | 110 Ds darmstadtium – | 111 Rg roentgenium – | 112 Cn copernicium – | 113 Nh nihonium – | 114 Fl flerovium – | 115 Mc moscovium – | 116 Lv livermorium – | 117 Ts tennessine – | 118 Og oganesson – |
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lanthanoids | 57 La lanthanum 139 | 58 Ce cerium 140 | 59 Pr praseodymium 141 | 60 Nd neodymium 144 | 61 Pm promethium – | 62 Sm samarium 150 | 63 Eu europium 152 | 64 Gd gadolinium 157 | 65 Tb terbium 159 | 66 Dy dysprosium 163 | 67 Ho holmium 165 | 68 Er erbium 167 | 69 Tm thulium 169 | 70 Yb ytterbium 173 | 71 Lu lutetium 175 |
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actinoids | 89 Ac actinium – | 90 Th thorium 232 | 91 Pa protactinium 231 | 92 U uranium 238 | 93 Np neptunium – | 94 Pu plutonium – | 95 Am americium – | 96 Cm curium – | 97 Bk berkelium – | 98 Cf californium – | 99 Es einsteinium – | 100 Fm fermium – | 101 Md mendelevium – | 102 No nobelium – | 103 Lr lawrencium – |
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The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).
The Avogadro constant, L = 6.02 × 1023 mol-1