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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 9 Hard
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.
Gases from a volcanic vent and from a farm are dried in a laboratory before they are analysed.
Four statements about drying these gases are listed.
Which statements are correct?
An extract from a crop plant contains two amino acids, a yellow pigment and a colourless sugar. The substances are separated by paper chromatography and each forms one separate spot.
The paper is dried and then sprayed with a locating agent. The locating agent reacts only with amino acids, to form purple spots.
How many spots can be seen on the paper before spraying and after spraying?
| before spraying | after spraying | |
|---|---|---|
| A | 1 | 2 |
| B | 0 | 3 |
| C | 1 | 3 |
| D | 1 | 4 |
Potassium-40, argon-40 and calcium-40 are found in rocks and are used to work out the age of the rocks.
The three nuclides are shown.
Which statements are correct?
An ion in the fallout from a nuclear accident has a charge of 2+, 36 electrons and a nucleon number of 90.
Radioactive ions like this can be taken up by crops growing in the soil.
How many more neutrons than electrons are in one of these ions?
Which row shows when sodium chloride conducts electricity?
| solid sodium chloride | molten sodium chloride | aqueous sodium chloride | |
|---|---|---|---|
| A | does not conduct | does not conduct | conducts |
| B | does not conduct | conducts | does not conduct |
| C | does not conduct | conducts | conducts |
| D | conducts | conducts | conducts |
Methanal, CH2O, is a molecule that has been detected in clouds of gas between the stars.
In a molecule of methanal the carbon atom is joined to the oxygen atom and to two hydrogen atoms, and every atom has a noble gas electronic configuration.
How many outer shell electrons in one molecule of methanal are not involved in bonding?
The propellers of ships are made of bronze.
The diagram shows a layer of atoms in bronze.
Which statement describes bronze?
Four solids, W, X, Y and Z, are found in rock samples from a geological survey.
Some of their properties are shown.
| solid | melting point / °C | conducts electricity when solid | conducts electricity when molten |
|---|---|---|---|
| W | 1085 | yes | yes |
| X | 2852 | no | yes |
| Y | 115 | no | no |
| Z | 1710 | no | no |
Which statement is correct?
Solid carbon dioxide, found in the polar ice caps of Mars, changes to a gas well below room temperature.
Grains of quartz (silicon dioxide) stay solid above 1000 °C.
The diagram shows the structures of the two substances.
Which statement explains the difference?
Four fertilisers contain nitrogen and hydrogen.
In which compound is the ratio of the number of nitrogen atoms to the number of hydrogen atoms in one formula unit 1 : 4?
A trace metal, M, is needed by crops. It forms a phosphate with the formula M3(PO4)2.
What is the formula of the sulfate of M?
A farmer spreads 500 g of pure calcium nitrate, Ca(NO3)2, on a field as a fertiliser.
What mass of nitrogen is in this fertiliser?
Limestone from a quarry contains calcium carbonate and unreactive impurities.
A 5.00 g sample of limestone is heated strongly until its mass stops changing. Only the calcium carbonate decomposes.
The mass of the sample decreases by 1.76 g.
What is the percentage purity of the calcium carbonate in the limestone?
Which statements about the reactions of dilute acids are correct?
Potassium nitrate, a fertiliser, is made by adding aqueous potassium hydroxide to dilute nitric acid until the mixture is neutral.
Which row shows the ions that combine to form water and the ions that do not change?
| ions that combine to form water | ions that do not change | |
|---|---|---|
| A | H+ and NO3− | K+ and OH− |
| B | H+ and OH− | K+ and NO3− |
| C | K+ and NO3− | H+ and OH− |
| D | K+ and OH− | H+ and NO3− |
Crystals of zinc sulfate, used to treat zinc-deficient soil, are made from zinc and dilute sulfuric acid.
The steps in the method are listed in a mixed-up order.
Which order of the steps gives pure dry crystals of zinc sulfate?
Which gas turns damp blue litmus paper red and then bleaches it white?
Three aqueous solutions, X, Y and Z, are tested to find out whether they are oxidising agents or reducing agents.
Each solution is added to aqueous potassium iodide and to acidified potassium manganate(VII). The results are shown.
| solution | aqueous potassium iodide | acidified potassium manganate(VII) |
|---|---|---|
| X | turns brown | stays purple |
| Y | stays colourless | turns colourless |
| Z | turns brown | turns colourless |
Which statement is correct?
Molten sodium chloride is electrolysed using inert electrodes P and Q.
Which statement is correct?
Compound R is obtained from sea water and compound S from the brine of a salt lake. Both compounds are ionic.
Compound R contains only the elements with proton numbers 12 and 35. Compound S contains only the elements with proton numbers 19 and 53.
Each compound is melted and electrolysed separately using inert electrodes.
Which row shows the products at each electrode?
| molten compound R | molten compound S | |||
|---|---|---|---|---|
| negative electrode | positive electrode | negative electrode | positive electrode | |
| A | magnesium | bromine | potassium | iodine |
| B | bromine | magnesium | iodine | potassium |
| C | magnesium | bromine | iodine | potassium |
| D | bromine | magnesium | potassium | iodine |
Four aqueous solutions are electrolysed separately using inert electrodes.
In which electrolyses are the products at both electrodes gases?
Rocks and soil contain many elements from Period 3 of the Periodic Table.
Element J conducts electricity when solid. Element K, in the same period, does not.
Which statement about J and K must be correct?
Rubidium, Rb, is a metal in Group 1. Some satellites carry atomic clocks that contain rubidium.
Rubidium is directly below potassium in the Periodic Table.
Which row gives correct predictions about rubidium?
| melting point compared with potassium | number of occupied electron shells in a rubidium atom | formula of rubidium sulfate | |
|---|---|---|---|
| A | higher | 5 | Rb2SO4 |
| B | lower | 4 | Rb2SO4 |
| C | lower | 5 | Rb2SO4 |
| D | lower | 5 | RbSO4 |
Helium, which has a proton number of 2, is used in balloons that carry weather instruments into the upper atmosphere.
Which statement explains, in terms of electronic configuration, why helium is unreactive?
Metals are obtained from oxide ores. Four mixtures, each of a metal powder and a metal oxide powder, are heated strongly.
Which mixture reacts?
A geologist extracts four metals, P, Q, R and S, from ores. In each of four experiments a metal is added to the aqueous nitrate of another metal.
The table shows whether a reaction occurs.
| metal added | aqueous solution of | result |
|---|---|---|
| P | Q nitrate | reaction |
| R | P nitrate | no reaction |
| S | R nitrate | reaction |
| Q | S nitrate | reaction |
What is the order of reactivity of the metals, from most reactive to least reactive?
A steel pipeline buried in damp soil is protected from rusting by blocks of magnesium connected to it.
Which row describes what happens?
| the magnesium blocks | the steel pipeline while the blocks are attached | the steel pipeline after all the magnesium has gone | |
|---|---|---|---|
| A | do not change | does not rust | stays protected |
| B | corrode | does not rust | starts to rust |
| C | corrode | rusts slowly | starts to rust |
| D | corrode | does not rust | stays protected |
A rocket engine burns hydrogen in oxygen to form steam.
Which row describes the bonds that are broken in this reaction and the energy change when the new bonds form?
| bonds broken in the reaction | energy change when the new bonds form | |
|---|---|---|
| A | O–H | endothermic |
| B | O–H | exothermic |
| C | H–H and O=O | exothermic |
| D | H–H and O=O | endothermic |
Hydrogen for the manufacture of fertilisers can be made from methane and steam.
Four statements about the energy changes in this reaction are listed.
Which statements are correct?
In a thruster on a satellite, hydrazine, N2H4, decomposes quickly as it passes over a solid metal catalyst.
Which statement explains why the catalyst increases the rate of the reaction?
A piece of fresh potato, which contains an enzyme, is added to hydrogen peroxide solution. The total volume of oxygen collected is measured every 30 s.
| time / s | 0 | 30 | 60 | 90 | 120 | 150 | 180 |
|---|---|---|---|---|---|---|---|
| volume of oxygen / cm3 | 0 | 24 | 42 | 54 | 60 | 60 | 60 |
Which statements are correct?
An alkane is separated from the crude oil pumped out of a rock formation under the sea bed.
Its relative molecular mass is 114.
What is the molecular formula of the alkane?
Four compounds are shown.
Which compounds turn aqueous bromine from orange to colourless?
Molecules of an oil from an oilseed crop each contain three C=C double bonds.
0.50 mol of the oil is changed into a solid margarine by reacting it with hydrogen. All the C=C double bonds react.
What amount of hydrogen molecules is needed?
Farmers in some countries grow maize so that ethanol can be made from it by fermentation.
Which row shows what ethanol forms in each reaction?
| burning in plentiful air | warming with acidified potassium manganate(VII) | |
|---|---|---|
| A | carbon dioxide and water | ethyl ethanoate |
| B | carbon dioxide and water | ethanoic acid |
| C | carbon monoxide and water | ethanoic acid |
| D | ethanoic acid and water | carbon dioxide and water |
Butyl ethanoate is an ester with a fruity smell. It is made by warming ethanoic acid with butan-1-ol and a few drops of concentrated sulfuric acid.
12.0 g of ethanoic acid is warmed with 7.4 g of butan-1-ol.
What is the maximum mass of butyl ethanoate that can form?
The displayed formula of an ester used in fruit flavourings is shown.
Which row shows the carboxylic acid and the alcohol that react to form this ester?
| carboxylic acid | alcohol | |
|---|---|---|
| A | methanoic acid | butan-1-ol |
| B | ethanoic acid | propan-1-ol |
| C | propanoic acid | ethanol |
| D | butanoic acid | methanol |
A research team designs an addition polymer for irrigation pipes on farms. The monomer is but-2-ene, CH3CH=CHCH3.
Which shows the repeat unit of the polymer?
Plastic waste is collected from beaches and from the surface of the ocean. Four ways of dealing with the waste are listed.
Which processes are chemical methods of recycling plastics?
A large area of forest is cleared and burned to make farmland.
Which row describes the effect on the carbon cycle?
| carbon dioxide added to the air by combustion | carbon dioxide removed from the air by photosynthesis | |
|---|---|---|
| A | increases | increases |
| B | decreases | increases |
| C | decreases | decreases |
| D | increases | decreases |
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