chermistry.com
Practice paper written from an analysis of every
O-Level Science (Chemistry) paper, 2010–2025

CANDIDATE
NAME

CENTRE
NUMBER

INDEX
NUMBER

SCIENCE (CHEMISTRY)

Specimen 2026

Paper 3 Chemistry

FORECAST PAPER · PAPER 3.8

For practice before the 2026 examination

1 hour 15 minutes

Candidates answer on the Question Paper.

No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Write your name, centre number and index number in the boxes above.

You may use an HB pencil for any diagrams, graphs or rough working.

Write in dark blue or black pen.

Do not use staples, paper clips, glue or correction fluid.

The use of an approved scientific calculator is expected, where appropriate.

You may lose marks if you do not show your working or if you do not use appropriate units.

Section A
Answer all questions.
Write your answers in the spaces provided on the question paper.

Section B
Answer one question.
Write your answers in the spaces provided on the question paper.

A copy of the Data Sheet is printed on page 17.
A copy of the Periodic Table is printed on page 18.

The number of marks is given in brackets [ ] at the end of each question or part question.

The total mark for this paper is 65.

This document consists of 18 printed pages.

NOT AN OFFICIAL EXAMINATION PAPER
Written for classroom practice from the topic frequencies in the chermistry theory-paper analysis. It follows the layout, wording and mark scheme conventions of the O-Level Science (Chemistry) papers but is not set, endorsed or marked by any examination board.

Section AAnswer all the questions in the spaces provided.

Farmers and gardeners often need to separate mixtures. Fig. 1.1 shows three jobs, A, B and C, and five separation methods.

Fig. 1.1

Draw one straight line from each job to the separation method that is most suitable for the job.

Each method can be used once, more than once or not at all.

[3]

Nitrate fertilisers supply nitrogen to plants. Four students, A, B, C and D, make statements about atoms and ions of nitrogen and oxygen.

Some of the statements are correct and some are incorrect.

Complete Table 2.1. Put a tick (✓) in one box in each row. If a statement is incorrect, write a correct statement in the last column.

Table 2.1
student	statement	correct	incorrect	if the statement is incorrect, write a correct statement
A	An atom of nitrogen-14, 147N, contains 7 protons, 7 neutrons and 7 electrons.
B	Atoms of nitrogen-14 and nitrogen-15 are isotopes of nitrogen because they have different numbers of protons.
C	An oxide ion, O²⁻, has 8 protons and 6 electrons because it has lost two electrons.
D	Almost all the mass of an atom is in the nucleus because electrons have a much smaller mass than protons and neutrons.

[4]

Read the passage about the casting of gold jewellery.

In lost-wax casting, a jeweller makes a model of a ring from paraffin wax, which melts at 58 °C. The model is covered with a hard mould that contains calcium carbonate. The mould is heated so that the wax melts and runs out. Molten 18-carat gold, which is an alloy of gold with copper and silver, is then poured into the empty mould. Pure gold melts at 1064 °C but the 18-carat gold alloy melts at about 900 °C. When the gold has cooled, the mould is broken open to remove the ring.

(a)

Complete Table 3.1 by choosing one type of structure and bonding for each material.
Choose from ionic, metallic and simple molecular.

Table 3.1
material	type of structure and bonding
gold
paraffin wax
calcium carbonate

[3]

(b)

Describe what is meant by the term alloy.

[1]

(c)

Paraffin wax does not conduct electricity.
State why.

[1]

(d)

Use ideas about the forces between particles to explain why paraffin wax melts at a much lower temperature than gold.

[1]

[Total: 6]

Copper(II) sulfate solution is sprayed on garden plants to control fungal diseases. It is made by adding black copper(II) oxide to dilute sulfuric acid.

CuO(s) + H₂SO₄(aq) → CuSO₄(aq) + H₂O(l)

Three students, A, B and C, each make a claim about the reaction.

Complete Table 4.1. Put a tick (✓) in one box in each row. If a claim is incorrect, write a correct statement in the last column.

Table 4.1
student	claim	correct	incorrect	if the claim is incorrect, write a correct statement
A	Copper(II) oxide is a basic oxide because it dissolves in water.
B	Hydrogen gas is formed in the reaction.
C	The solution turns blue.

[5]

Zinc is used to coat steel fence posts on a farm. A student reacts zinc strips with dilute hydrochloric acid to investigate the rate of reaction.

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

Fig. 5.1 shows the hydrogen ions in the same volume of acid, and a zinc strip, at the start of three experiments. The zinc strip is the same size and the temperature is the same in each experiment.

Fig. 5.1

In experiment B, the temperature of the mixture rises from 22.0 °C to 31.5 °C.

(a)

Use Fig. 5.1 to compare the concentration of hydrogen ions in experiment A with that in experiment B.

[1]

(b)

State which experiment, A or B, has the greater rate of reaction at the start.
Explain your answer. Use ideas about collisions between particles.

[2]

(c)

In experiment C, the concentration of hydrogen ions is half the concentration in experiment A.
Draw hydrogen ions in the box for experiment C on Fig. 5.1. Draw each ion as a circle with a + sign inside.

[1]

(d)

State whether the reaction in experiment B is exothermic or endothermic.
Give a reason for your answer.

[1]

[Total: 5]

A farm grows sugar cane and keeps cattle. The tractors use diesel. Fig. 6.1 shows part of the carbon cycle on the farm.

Fig. 6.1

(a)

Name process P.

[1]

(b)

Name process Q.

[1]

(c)

Cattle also release methane, CH₄, into the air.
Describe the effect on the environment of increasing the amount of methane in the air.

[1]

(d)

Some of the sugar cane is used to make bioethanol, which is used as a fuel in the tractors.
Write a word equation for the complete combustion of ethanol.

[1]

(e)

Explain why burning bioethanol adds little extra carbon dioxide to the air.

[1]

[Total: 5]

A garden-supplies shop sells four solutions, P, Q, R and S. Each solution contains one cation and one anion. The anion is chloride, nitrate or sulfate. Table 7.1 shows the results of some tests on the solutions.

Table 7.1
solution	aqueous sodium hydroxide, added until in excess	aqueous ammonia, added until in excess	dilute nitric acid, then aqueous silver nitrate	dilute nitric acid, then aqueous barium nitrate
P	red-brown precipitate, insoluble in excess	red-brown precipitate, insoluble in excess	no change	white precipitate
Q	green precipitate, insoluble in excess	green precipitate, insoluble in excess	no change	no change
R	white precipitate, dissolves in excess	white precipitate, dissolves in excess	white precipitate	no change
S	no precipitate; on warming, a gas that turns damp red litmus paper blue	no change	no change	white precipitate

(a)

Table 7.2 shows conclusions that four students make from Table 7.1.
Complete Table 7.2. Put a tick (✓) in one box in each row. If a conclusion is incorrect, write a correct conclusion in the last column.

Table 7.2
student	conclusion	correct	incorrect	if the conclusion is incorrect, write a correct conclusion
1	P contains iron(II) ions.
2	Q contains iron(II) ions.
3	R contains aluminium ions.
4	S contains sulfate ions.

[4]

(b)

Use Table 7.1 to identify the anion in each of P, Q and R.

[3]

(c)

Write a balanced chemical equation, including state symbols, for the reaction of solution Q with aqueous sodium hydroxide.

[3]

[Total: 10]

Calcium nitrate, Ca(NO₃)₂, is a fertiliser that growers dissolve in the water supplied to plants in a greenhouse. A grower tests a fertiliser solution by adding excess sodium carbonate solution to it. A precipitate of calcium carbonate forms. Table 8.1 shows the measurements.

Ca(NO₃)₂(aq) + Na₂CO₃(aq) → CaCO₃(s) + 2NaNO₃(aq)

Table 8.1
mass of calcium nitrate dissolved / g	total volume of solution made / cm³	volume of solution taken for the test / cm³
8.20	250	50.0

[A_r: C, 12; N, 14; O, 16; Ca, 40]

(a)

Calculate the relative formula mass, M_r, of calcium nitrate, Ca(NO₃)₂.

M_r =[1]

(b)

Calculate the amount, in moles, of calcium nitrate in 8.20 g.

amount =mol[1]

(c)

Calculate the concentration of calcium nitrate in the 250 cm³ of fertiliser solution, in mol / dm³.

concentration =mol / dm³[1]

(d)

Calculate the concentration of calcium nitrate in the fertiliser solution, in g / dm³.

concentration =g / dm³[1]

(e)

A 50.0 cm³ sample of the fertiliser solution is taken for the test.
Calculate the amount, in moles, of calcium nitrate in the sample.

amount =mol[1]

(f)

Excess sodium carbonate solution is added to the 50.0 cm³ sample.
Calculate the mass of calcium carbonate that forms.

mass =g[2]

[Total: 7]

Read the passage about poly(ethene). Table 9.1 shows the melting points and boiling points of some alkenes.

Farmers use thin poly(ethene) film to cover polytunnels and to cover the soil between rows of crops. Poly(ethene) is made from ethene, C₂H₄, which is made on a large scale from the large molecules in crude oil. Ethene is a gas at room temperature.
At the end of the season, much of the used film is left in the fields. Some farmers burn the used film in the open instead.

Table 9.1
name	molecular formula	melting point / °C	boiling point / °C
ethene	C₂H₄	−169	−104
propene	C₃H₆	−185	−48
but-1-ene	C₄H₈	−185	−6
pent-1-ene	C₅H₁₀	−165	30
hex-1-ene	C₆H₁₂	−140	63
hept-1-ene	C₇H₁₄	−119

(a)

Ethene belongs to the homologous series of alkenes.

(i)

State the general formula of the alkenes.

[1]

(ii)

Use the data in Table 9.1 to predict the boiling point of hept-1-ene.

boiling point =°C[1]

(iii)

Use Table 9.1 and your answer to (ii) to predict the physical state of hept-1-ene at room temperature, 25 °C.
Give a reason for your answer.

[1]

(b)

Suggest two reasons why burning the used poly(ethene) film is not recommended.
Use ideas about the products of burning.

[2]

(c)

Ethene is made by cracking. Complete the equation for the cracking of octane, C₈H₁₈.

C₈H₁₈ → C₂H₄ + .......................

[1]

(d)

Ethene is the monomer of poly(ethene). Fig. 9.1 shows the displayed formula of ethene.

Fig. 9.1

State what is meant by addition polymerisation and explain why ethene can undergo it.

[2]

(e)

Poly(ethene) film that is left in the fields causes pollution.

(i)

State one pollution problem caused by the disposal of plastics such as poly(ethene).

[1]

(ii)

Describe one way of recycling poly(ethene) film.

[1]

[Total: 10]

Section BAnswer one question from this section.

Metals have many uses on farms and in gardens. Read the information about metals and answer the questions.

Metals in the garden shed

A gardener keeps four metal objects in a shed: a lawnmower deck made of magnesium, a watering can made of zinc, a spade with an iron blade and a water pipe made of copper.

A student compares the reactivity of the four metals. She adds equal-sized pieces of each metal to the same volume of dilute hydrochloric acid at 25 °C and measures the volume of gas collected in the first two minutes. Table 10.1 shows her results.

People did not learn to obtain all metals from their ores at the same time. Table 10.2 shows approximately how long ago people first obtained three of the metals.

Table 10.1
metal	volume of gas in 2 minutes / cm³
magnesium	96
zinc	36
iron	12
copper	0

Table 10.2
metal	approximate time since first obtained / years
copper	7 000
iron	3 000
magnesium	200

(a)

Use Table 10.1 to put the four metals in order of reactivity. Start with the most reactive.

[2]

(b)

Name the gas collected when a metal reacts with dilute hydrochloric acid.

[1]

(c)

No gas is collected from copper. Suggest why copper is a suitable metal for a pipe that carries water around a farm.

[1]

(d)

Use Table 10.2 and your answer to (a) to suggest why people obtained magnesium from its ore much more recently than copper and iron.

[1]

(e)

Carbon can be heated with the oxide of a metal to obtain the metal. Table 10.3 shows the temperature needed to remove the oxygen from four metal oxides.

Table 10.3
oxide	approximate temperature needed / °C
copper(II) oxide	500
iron(III) oxide	800
zinc oxide	1000
magnesium oxide	1900

(i)

Describe how the temperature needed changes as the reactivity of the metal increases.

[1]

(ii)

Lead is less reactive than iron but more reactive than copper. Predict the approximate temperature needed to remove the oxygen from lead(II) oxide using carbon.

[1]

(f)

Anhydrous calcium chloride is kept in the shed to absorb water vapour from the air. Calcium chloride is an ionic compound. Draw a 'dot-and-cross' diagram to show the bonding in calcium chloride. Show only the outer shell electrons. Include the charge on each ion.

[Proton numbers: Ca, 20; Cl, 17]

[2]

(g)

Calcium burns in oxygen to form calcium oxide. The equation for the reaction is shown.

2Ca + O₂ → 2CaO

State the change in the oxidation state of calcium in this reaction.

[1]

[Total: 10]

Iron is the metal most widely used on farms and in gardens.

Fig. 11.1 shows three reactions of iron. The letters are not the chemical symbols.

Fig. 11.1

(a)

Complete Fig. 11.1. Write the name of each of P, Q, R and S.

[2]

(b)

State one observation that shows a reaction occurs when iron is added to dilute hydrochloric acid (reaction 1).

[1]

(c)

Copper does not react with steam or with dilute hydrochloric acid. Explain why this shows that copper is less reactive than iron.

[1]

(d)

Potassium reacts violently with cold water. Iron does not react with cold water. Suggest whether potassium is easier or harder than iron to obtain from its ore. Explain your answer.

[1]

(e)

(i)

Iron fencing wire is covered with a layer of plastic. Explain how the plastic stops the iron from rusting.

[1]

(ii)

State one other way to stop iron from rusting.

[1]

(f)

Growers add carbon dioxide to the air in a greenhouse to help plants grow. Carbon dioxide is a covalent compound. Draw a 'dot-and-cross' diagram to show the bonding in a molecule of carbon dioxide. Show only the outer shell electrons.

[Proton numbers: C, 6; O, 8]

[2]

(g)

The ionic equation for reaction 1 is shown.

Fe + 2H⁺ → Fe²⁺ + H₂

Identify the reducing agent in this reaction. Give a reason for your answer.

[1]

[Total: 10]

Data Sheet

Colours of Some Common Metal Hydroxides

aluminium hydroxide	white
calcium hydroxide	white
copper(II) hydroxide	light blue
iron(II) hydroxide	green
iron(III) hydroxide	red-brown
zinc hydroxide	white

The Periodic Table of Elements

Group

Key

hydrogen

helium

lithium

beryllium

proton (atomic) number

atomic symbol

name

relative atomic mass

boron

carbon

nitrogen

oxygen

fluorine

neon

sodium

magnesium

aluminium

silicon

phosphorus

sulfur

chlorine

35.5

argon

potassium

calcium

scandium

titanium

vanadium

chromium

manganese

iron

cobalt

nickel

copper

zinc

gallium

germanium

arsenic

selenium

bromine

krypton

rubidium

strontium

yttrium

zirconium

niobium

molybdenum

technetium

–

ruthenium

101

rhodium

103

palladium

106

silver

108

cadmium

112

indium

115

tin

119

antimony

122

tellurium

128

iodine

127

xenon

131

caesium

133

barium

137

57–71

lanthanoids

hafnium

178

tantalum

181

tungsten

184

rhenium

186

osmium

190

iridium

192

platinum

195

gold

197

mercury

201

thallium

204

lead

207

bismuth

209

polonium

–

astatine

–

radon

–

francium

–

radium

–

89–103

actinoids

104

rutherfordium

–

105

dubnium

–

106

seaborgium

–

107

bohrium

–

108

hassium

–

109

meitnerium

–

110

darmstadtium

–

111

roentgenium

–

112

copernicium

–

113

nihonium

–

114

flerovium

–

115

moscovium

–

116

livermorium

–

117

tennessine

–

118

oganesson

–

lanthanoids

lanthanum

139

cerium

140

praseodymium

141

neodymium

144

promethium

–

samarium

150

europium

152

gadolinium

157

terbium

159

dysprosium

163

holmium

165

erbium

167

thulium

169

ytterbium

173

lutetium

175

actinoids

actinium

–

thorium

232

protactinium

231

uranium

238

neptunium

–

plutonium

–

americium

–

curium

–

berkelium

–

californium

–

einsteinium

–

100

fermium

–

101

mendelevium

–

102

nobelium

–

103

lawrencium

–

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