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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 4 Easy
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.
The apparatus shown is used to collect a gas that is made in a flask.
The properties of four gases are shown. The letters are not the chemical symbols.
| gas | solubility in water | density compared with air |
|---|---|---|
| W | very soluble | less dense |
| X | soluble | denser |
| Y | insoluble | denser |
| Z | very soluble | denser |
Which gas can be collected using this apparatus?
Muddy river water contains insoluble mud and dissolved salts.
The mud is removed first, and then pure water is obtained from the clear liquid.
Which row shows a suitable method for each stage?
| removing the mud | obtaining pure water | |
|---|---|---|
| A | evaporation | crystallisation |
| B | evaporation | distillation |
| C | filtration | crystallisation |
| D | filtration | distillation |
Lithium is a metal used in rechargeable batteries.
An atom of lithium has 3 protons, 4 neutrons and 3 electrons.
Which diagram shows the structure of this atom?
Menthol is a covalent compound with a simple molecular structure.
Menthol, which gives some cough sweets their cooling taste, melts at about 42 °C.
Which statement explains why menthol has a low melting point?
A compound of iron and chlorine is used to remove suspended particles from drinking water.
The formula of an iron ion in the compound is Fe3+ and the formula of a chloride ion is Cl−.
What is the formula of the compound?
Most crops grow best in neutral soil.
The soil in a farmer’s field is too acidic, so the farmer adds calcium hydroxide to it.
Which row describes calcium hydroxide and its effect on the soil?
| type of substance | effect on the pH of the soil | |
|---|---|---|
| A | acid | increases |
| B | acid | decreases |
| C | base | increases |
| D | base | decreases |
Milk of magnesia is a medicine that contains magnesium hydroxide.
Magnesium hydroxide reacts with the hydrochloric acid in the stomach.
Which products form in this reaction?
In photosynthesis, plants make glucose from carbon dioxide and water.
Which substance is reduced?
Which statement about the elements in Period 3 of the Periodic Table is correct?
Which row describes sodium compared with potassium?
| melting point | reaction with water | |
|---|---|---|
| A | higher | less vigorous |
| B | higher | more vigorous |
| C | lower | less vigorous |
| D | lower | more vigorous |
Acid rain damages marble statues.
A student adds marble chips to dilute hydrochloric acid of different concentrations.
The same volume of acid and the same mass of marble chips are used each time.
The time taken to collect 40 cm3 of gas is measured.
| concentration of acid / mol / dm3 | time to collect 40 cm3 of gas / s |
|---|---|
| 0.5 | 120 |
| 1.0 | 60 |
| 1.5 | 40 |
| 2.0 | 30 |
Which conclusion is supported by the results?
Natural gas, which is mainly methane, and crude oil formed over millions of years from the remains of tiny sea creatures.
Which statement explains why they are non-renewable sources of energy?
Propane, which is used as the fuel in outdoor gas barbecues, is an alkane.
Four statements about alkanes are listed.
Which two statements are correct?
Which diagram shows a molecule of ethene?
Fish oil capsules, taken as a food supplement, contain polyunsaturated fats.
Which statements about polyunsaturated fats are correct?
Some hand sanitisers contain an alcohol.
The displayed formula of this alcohol is shown.
What is the name of this alcohol?
Bioethanol is left in the open fuel tank of a garden tool for several months.
The liquid slowly becomes acidic because ethanoic acid forms.
Which process converts the ethanol into ethanoic acid?
A hospital cylinder holds dry air that contains 126 dm3 of oxygen.
What is the approximate volume of the dry air in the cylinder?
Which natural process releases sulfur dioxide into the air?
Which row describes methane in the atmosphere?
| a source of methane | effect of increased levels | |
|---|---|---|
| A | burning of coal | global warming |
| B | burning of coal | acid rain |
| C | rotting vegetation | global warming |
| D | rotting vegetation | acid rain |
| 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