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Practice paper written from an analysis of every
O-Level Chemistry paper, 2009–2025
Paper 1 Multiple Choice
FORECAST PAPER
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 18.
The use of an approved scientific calculator is expected, where appropriate.
Gases are dried before they are collected.
Calcium oxide and concentrated sulfuric acid are two drying agents.
Which gas can be dried using both of these drying agents?
A student uses paper chromatography to compare two mixtures of dyes, M and N, with four known dyes P, Q, R and S.
The chromatogram is shown.
Which dye is present in both M and N?
A student wants to separate the two substances in a mixture.
Which mixture is best separated using a separating funnel?
Substance Y is a liquid at 90 °C.
Y is cooled at a steady rate and its temperature is measured every minute.
The results are shown.
What happens to the particles of Y in region Q?
Two isotopes of chlorine are shown in the table.
| isotope | protons | neutrons |
|---|---|---|
| chlorine-35 | 17 | 18 |
| chlorine-37 | 17 | 20 |
Which statement about atoms of these two isotopes is correct?
Atoms of element Q have the electronic configuration 2,8,2.
Atoms of element R have the electronic configuration 2,5.
Q and R react to form an ionic compound.
The letters are not the chemical symbols.
What is the formula of the compound?
A sample contains 0.10 mol of oxygen molecules, O2.
How many outer shell electrons in the sample are not involved in bonding between the atoms?
The tips of some cutting tools are made of diamond.
Which statement explains why diamond is used for this purpose?
Bronze is an alloy of copper and tin.
Bronze is harder than pure copper.
Which statement explains why?
Aqueous lead(II) nitrate is mixed with aqueous potassium iodide.
A yellow precipitate of lead(II) iodide forms.
Which ionic equation, including state symbols, represents the reaction?
Aluminium reacts with dilute hydrochloric acid.
A student adds 1.35 g of aluminium to 100 cm3 of 1.0 mol / dm3 hydrochloric acid.
What is the volume of hydrogen formed at room temperature and pressure?
Copper(II) carbonate decomposes when it is heated strongly.
A sample of 6.2 g of copper(II) carbonate is heated until it has decomposed completely.
What is the mass of copper(II) oxide formed?
A sample of an oxide of lead contains 6.21 g of lead and 0.64 g of oxygen.
What is the empirical formula of this oxide of lead?
Aqueous ammonia is neutralised by dilute sulfuric acid.
20.0 cm3 of aqueous ammonia is just neutralised by 25.0 cm3 of 0.040 mol / dm3 sulfuric acid.
What is the concentration of the aqueous ammonia in g / dm3?
Nitric acid is a strong acid and methanoic acid is a weak acid.
Both acids have a concentration of 0.10 mol / dm3.
Equal volumes of the two acids are tested. Excess calcium carbonate is then added to each volume of acid.
Which row compares methanoic acid with nitric acid?
| electrical conductivity of the acid | total volume of carbon dioxide formed | |
|---|---|---|
| A | lower | smaller |
| B | lower | the same |
| C | higher | smaller |
| D | higher | the same |
Aqueous sodium hydroxide is added slowly to dilute hydrochloric acid in a flask.
The pH of the mixture is measured as the alkali is added.
The results are shown.
At which point does the mixture contain equal concentrations of H+ ions and OH− ions?
Aqueous solutions of two different salts are mixed.
In which mixture does no precipitate form?
A student makes zinc chloride by adding solid zinc carbonate to dilute hydrochloric acid.
Zinc carbonate is added until some of it remains undissolved.
Why is an excess of zinc carbonate used?
Aqueous solution X contains one cation and one anion.
The results of three tests on X are shown.
| test | method | observation |
|---|---|---|
| 1 | add aqueous sodium hydroxide dropwise, then in excess | light blue precipitate, insoluble in excess |
| 2 | add aqueous ammonia dropwise, then in excess | light blue precipitate, which dissolves in excess to give a dark blue solution |
| 3 | add aqueous sodium hydroxide, then aluminium foil, and warm | gas given off turns damp red litmus paper blue |
What is X?
Sulfur dioxide and carbon dioxide are both colourless gases.
Which test distinguishes sulfur dioxide from carbon dioxide?
Four reactions are represented by the equations shown.
Which equation represents a redox reaction?
Aqueous potassium iodide is colourless.
Substance W is added to aqueous potassium iodide.
The mixture turns brown.
Which statement about W is correct?
Zinc iodide is heated until it melts.
The molten compound is electrolysed using inert electrodes P and Q.
Electrode P is connected to the negative terminal of the power supply and electrode Q to the positive terminal.
At which electrode is zinc formed, and why?
An iron key is electroplated with copper.
The key is connected to the negative terminal of a power supply and a copper rod is connected to the positive terminal.
Both dip into aqueous copper(II) sulfate.
Which row describes the changes at the electrodes?
| at the iron key | at the copper rod | |
|---|---|---|
| A | a layer of copper forms | oxygen gas forms |
| B | a layer of copper forms | the copper rod dissolves |
| C | hydrogen gas forms | oxygen gas forms |
| D | the copper rod dissolves | a layer of copper forms |
An ion of element T has a charge of 3+.
The electronic structure of the ion is 2,8.
The letter is not the chemical symbol.
In which Group and Period of the Periodic Table is T found?
| Group | Period | |
|---|---|---|
| A | 3 | 3 |
| B | 13 | 2 |
| C | 13 | 3 |
| D | 15 | 2 |
At room temperature, chlorine is a yellow-green gas, bromine is a red-brown liquid and iodine is a grey-black solid.
Astatine is the next element below iodine in Group 17.
What is the most likely appearance of astatine at room temperature?
Aqueous solutions of chlorine, bromine and iodine are added separately to aqueous solutions of potassium chloride, potassium bromide and potassium iodide.
Which equation represents a reaction that occurs?
Iron forms two sulfates. Iron(II) sulfate contains Fe2+ ions and SO42− ions.
Iron(III) sulfate contains Fe3+ ions and SO42− ions.
What is the formula of iron(III) sulfate?
Four metals P, Q, R and S are tested.
Each metal is added to dilute hydrochloric acid, and the oxide of each metal is heated strongly with carbon.
The letters are not the chemical symbols.
| metal | dilute hydrochloric acid | oxide heated with carbon |
|---|---|---|
| P | bubbles very rapidly | no reaction |
| Q | bubbles slowly | metal forms |
| R | no reaction | metal forms |
| S | bubbles rapidly | metal forms |
What is the order of reactivity, from most reactive to least reactive?
A reaction has an activation energy of 150 kJ / mol and an enthalpy change, ΔH, of −50 kJ / mol.
In each diagram the reactants have an energy of 100 kJ / mol.
Which energy profile diagram represents this reaction?
The energy taken in to break the bonds in the reactants and the energy released when the bonds in the products form are shown for four reactions.
| reaction | energy taken in to break bonds / kJ | energy released when bonds form / kJ |
|---|---|---|
| P | 900 | 700 |
| Q | 1200 | 1500 |
| R | 1100 | 1000 |
| S | 600 | 850 |
Which reaction is the most endothermic?
50 cm3 of 2.0 mol / dm3 hydrochloric acid, which is in excess, is added to 1.0 g of marble chips (calcium carbonate) in an open flask on a balance.
The mass of the flask and its contents decreases because carbon dioxide escapes. Curve X shows the results.
A second experiment gives curve Y. All other conditions are the same as for curve X, apart from the one change.
Which change gives curve Y?
Ethene reacts with hydrogen to form ethane.
The solid line in each diagram is the energy profile for the reaction without a catalyst.
The reaction is repeated with finely divided nickel as a catalyst. The dashed line shows the profile with nickel.
Which diagram is correct?
An alkene reacts with hydrogen in the presence of a nickel catalyst.
The only organic product is 2-methylpropane, CH3CH(CH3)CH3.
Which structure shows the alkene?
Butan-1-ol has the structure CH3CH2CH2CH2OH.
Which alcohol is an isomer of butan-1-ol?
Butan-1-ol is warmed with acidified potassium manganate(VII).
Which row describes the colour change of the mixture and the organic product?
| colour change | organic product | |
|---|---|---|
| A | purple to colourless | butanoic acid |
| B | purple to colourless | butyl butanoate |
| C | colourless to purple | butanoic acid |
| D | colourless to purple | butyl butanoate |
Aqueous glucose is fermented by yeast to form ethanol and gas X.
What is X?
Part of an addition polymer is shown.
Which monomer is used to make this polymer?
Ethanoic acid reacts with butan-1-ol in the presence of a catalyst to form an ester and water.
What is the name of the ester?
Calcium carbonate is used in the flue gases of power stations to remove sulfur dioxide.
Which statement about the redox changes in this reaction is correct?
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