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Practice paper written from an analysis of every
O-Level Chemistry paper, 2009–2026
Paper 1 Multiple Choice
FORECAST PAPER · SET 8 Medium
For practice before the 2026 examination
1 hour
Additional Materials: Paper for your answers, numbered 1 to 40
Write in soft pencil.
Do not use staples, paper clips, glue or correction fluid.
There are forty 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 40.
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 Periodic Table is printed on page 16.
The use of an approved scientific calculator is expected, where appropriate.
A bag of sand for sand art has been contaminated with sodium chloride and ammonium chloride.
Ammonium chloride changes directly from a solid to a gas when it is heated, and changes back to a solid on a cold surface. Sodium chloride and sand do not change when they are heated. Sodium chloride and ammonium chloride dissolve in water; sand does not.
Which method can be used to obtain a separate sample of each of the three substances?
A company makes eye make-up. It measures the purity of each pigment before the pigment is used.
Which statements give reasons why the purity of the pigment is important?
A few drops of perfume are sprayed in one corner of a closed room, where the air is still.
After several minutes, the smell is detected at the opposite side of the room.
Which statements about the perfume particles are correct?
The age of an old wooden sculpture can be found using carbon-14. Atoms of carbon-14 and carbon-12 are isotopes of carbon.
Which row compares the numbers of particles in an atom of carbon-14 with those in an atom of carbon-12?
| protons | neutrons | electrons | |
|---|---|---|---|
| A | the same | two more | the same |
| B | the same | two more | two more |
| C | two more | two more | two more |
| D | two more | the same | the same |
Sea salt crystals are used in body scrubs.
In the diagrams, + and − show positive and negative charges and the small black dots are electrons.
Which diagram represents the arrangement of the particles in a crystal of sodium chloride?
Solid carbon dioxide, dry ice, is used to make mist for stage shows. It is made of simple molecules and changes directly to a gas at −78 °C.
Which statement explains why it changes to a gas at such a low temperature?
Gold is beaten into thin sheets, called gold leaf, to decorate paintings and picture frames, and is drawn into wires for jewellery.
Which row explains why gold can be hammered into shape and why it conducts electricity?
| gold can be hammered into shape because | gold conducts electricity because | |
|---|---|---|
| A | layers of positive ions can slide over each other | delocalised electrons are free to move |
| B | layers of positive ions can slide over each other | positive ions are free to move |
| C | the metallic bonding is weak | delocalised electrons are free to move |
| D | the metallic bonding is weak | positive ions are free to move |
Sterling silver is an alloy of silver with a small amount of copper. It is harder than pure silver.
Which statements about sterling silver are correct?
Artists draw with graphite pencils. Jewellers set diamonds in rings.
Graphite and diamond are both made of carbon atoms only.
Which row correctly explains these properties of graphite and diamond?
| graphite leaves marks on paper because | graphite conducts electricity because | diamond is very hard because | |
|---|---|---|---|
| A | covalent bonds in the layers break easily | each carbon atom has a delocalised electron | each carbon atom is bonded strongly to four others |
| B | layers of carbon atoms slide off | each carbon atom has a delocalised electron | each carbon atom is bonded strongly to four others |
| C | layers of carbon atoms slide off | it contains mobile ions | each carbon atom is bonded strongly to four others |
| D | layers of carbon atoms slide off | each carbon atom has a delocalised electron | delocalised electrons hold its atoms together |
Aluminium sulfate, Al2(SO4)3, is used as a mordant to fix dye to cloth in textile crafts.
What is the relative formula mass, Mr, of aluminium sulfate?
Lactic acid is used in some skin-care creams. A sample of lactic acid contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass.
What is the molecular formula of lactic acid?
Soap is made by heating fats with aqueous sodium hydroxide.
A soap-maker dissolves 4.0 g of sodium hydroxide in water to make 500 cm3 of solution.
What is the concentration of the solution in mol / dm3?
Lactic acid is a weak acid that is used in skin-care creams.
Which diagram represents an aqueous solution of a weak acid, HA? (The water molecules are not shown.)
Lavender, which is grown to make perfumes and soaps, grows poorly in acidic soil.
A gardener adds calcium hydroxide to an acidic soil in which lavender is planted.
Which statements are correct?
In fresco painting, an artist paints on wet plaster made by adding water to quicklime, calcium oxide.
The plaster hardens as it reacts with carbon dioxide from the air.
Which row classifies the two oxides?
| calcium oxide | carbon dioxide | |
|---|---|---|
| A | acidic | basic |
| B | amphoteric | acidic |
| C | basic | acidic |
| D | basic | neutral |
In eco-printing, iron(II) sulfate is used to darken the colours of plant dyes when leaf patterns are printed on fabric.
Which method can be used to prepare crystals of iron(II) sulfate?
A cosmetics chemist tests the water used to make a face lotion for chloride ions.
Dilute nitric acid is added to the water before aqueous silver nitrate.
Why is the dilute nitric acid added first?
Silver jewellery turns black when it reacts with hydrogen sulfide and oxygen in the air.
Which statement about the reaction is correct?
Zinc chloride is heated until it melts. The molten zinc chloride is then electrolysed using graphite electrodes. The lamp lights.
Which statement about the electrolysis is correct?
Sodium sulfate is added to the dye bath when fabric is dyed.
Aqueous sodium sulfate is electrolysed using inert electrodes.
Which row shows the products at the electrodes?
| product at the negative electrode | product at the positive electrode | |
|---|---|---|
| A | hydrogen | oxygen |
| B | hydrogen | sulfur dioxide |
| C | sodium | oxygen |
| D | sodium | sulfur dioxide |
Aqueous silver nitrate is electrolysed using inert electrodes.
Silver metal forms at the cathode and oxygen gas forms at the anode.
Which row shows the correct ionic equations for the reactions at the electrodes?
| at the cathode | at the anode | |
|---|---|---|
| A | Ag+(aq) → Ag(s) + e− | 4OH−(aq) → 2H2O(l) + O2(g) + 4e− |
| B | Ag+(aq) → Ag(s) + e− | 2OH−(aq) → H2O(l) + O2(g) + 2e− |
| C | Ag+(aq) + e− → Ag(s) | 4OH−(aq) → 2H2O(l) + O2(g) + 2e− |
| D | Ag+(aq) + e− → Ag(s) | 4OH−(aq) → 2H2O(l) + O2(g) + 4e− |
A hydrogen fuel cell supplies the electricity for the lights of a stall at an outdoor craft fair.
Four statements about hydrogen and the fuel cell are listed.
Which statements are correct?
Ruby and sapphire are gemstones made mainly of aluminium oxide.
An aluminium atom has three outer electrons and an oxygen atom has six outer electrons.
What is the formula of aluminium oxide?
Which row describes an atom of a non-metal?
| number of outer electrons | when the atom forms an ion, it | |
|---|---|---|
| A | 2 | loses electrons |
| B | 3 | gains electrons |
| C | 6 | loses electrons |
| D | 7 | gains electrons |
The halogens are diatomic non-metals.
The table shows the melting points and boiling points of three of them.
| halogen | melting point / °C | boiling point / °C |
|---|---|---|
| chlorine | −101 | −34 |
| bromine | −7 | 59 |
| iodine | 114 | 184 |
Which row shows the states of the halogens at room temperature, 25 °C?
| chlorine | bromine | iodine | |
|---|---|---|---|
| A | gas | gas | solid |
| B | gas | liquid | liquid |
| C | gas | liquid | solid |
| D | liquid | liquid | solid |
Silver, copper, iron and zinc are all used by metalworkers and jewellers.
Which sequence shows the metals in order of increasing reactivity?
Magnesium, zinc and copper are used to make decorative objects.
Each metal is obtained from its ore either by electrolysis or by heating with carbon.
Which row shows how each metal is obtained?
| magnesium | zinc | copper | |
|---|---|---|---|
| A | electrolysis | heating with carbon | heating with carbon |
| B | electrolysis | electrolysis | heating with carbon |
| C | heating with carbon | heating with carbon | heating with carbon |
| D | electrolysis | heating with carbon | electrolysis |
Plaster of Paris is a powder used for casts and sculptures.
When it is mixed with water it sets and the mixture becomes warm.
The energy profile diagram for the reaction is shown.
Which row identifies the activation energy and the enthalpy change for the reaction?
| activation energy | enthalpy change | |
|---|---|---|
| A | X | Z |
| B | X | Y |
| C | Y | X |
| D | Z | Y |
Platinum, a metal used in jewellery, is a catalyst for the decomposition of hydrogen peroxide into water and oxygen.
The decomposition of 20 cm3 of hydrogen peroxide solution is carried out twice, once on its own and once with a disc of platinum. All other conditions are the same.
Which row compares the experiment with platinum with the experiment without it?
| rate of reaction | total volume of oxygen formed | |
|---|---|---|
| A | the same | greater |
| B | faster | greater |
| C | faster | the same |
| D | the same | the same |
A bath fizzer contains citric acid and sodium hydrogencarbonate.
It fizzes, giving off carbon dioxide, when it is placed in water.
A student investigates how the temperature of the water affects the rate of the reaction. One fizzer is added to water at each of four temperatures.
Four statements about the method are listed.
Which statements describe a suitable method?
A jeweller uses a spirit lamp to heat metal.
The lamp burns bioethanol made from sugarcane.
Four statements about bioethanol are listed.
Which statements are correct?
The table shows the molecular formulae and boiling points of four consecutive members of a homologous series of hydrocarbons.
| molecular formula | boiling point / °C |
|---|---|
| C3H6 | −48 |
| C4H8 | −6 |
| C5H10 | 30 |
| C6H12 | 63 |
Which statements about this series are correct?
A potter fires pots in a kiln that burns a gas.
Three statements about the gas are given.
Which gas is it?
Batik artists use wax that is a mixture of hydrocarbons with large molecules.
Large hydrocarbon molecules can be cracked into smaller molecules.
Which equation represents the cracking of the hydrocarbon C14H30?
Ethene reacts with bromine.
Which structure shows the organic product?
The structure of an organic acid used in leather craft is shown.
What is the name of this compound?
Pearls are mainly calcium carbonate.
A pearl is placed in ethanoic acid.
An ethanoate ion is CH3CO2−.
Which row shows the gas given off and the formula of the salt formed?
| gas given off | formula of the salt | |
|---|---|---|
| A | carbon dioxide | CH3CO2Ca |
| B | carbon dioxide | (CH3CO2)2Ca |
| C | hydrogen | CH3CO2Ca |
| D | hydrogen | (CH3CO2)2Ca |
Nylon is a man-made fibre.
Which row correctly describes nylon?
| a typical use | type of polymer | |
|---|---|---|
| A | clingfilm | polyamide |
| B | clingfilm | polyester |
| C | fishing line | polyamide |
| D | fishing line | polyester |
Three atmospheric pollutants, P, Q and R, are described.
Which row identifies P, Q and R?
| P | Q | R | |
|---|---|---|---|
| A | CO | SO2 | NO2 |
| B | CO | NO2 | SO2 |
| C | NO2 | CO | SO2 |
| D | SO2 | NO2 | CO |
In the past, aerosol hairsprays used chlorofluorocarbons (CFCs) as the propellant.
Which statement describes how CFCs damage the ozone layer?
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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