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2025 OCR GCSE (9−1) Chemistry B (Twenty First Century Science) J258/
Breadth in Chemistry (Higher Tier) May QUESTION PAPER and MARK
SCHEME
Oxford Cambridge and RSA
Monday 19 May 2025 – Morning
GCSE (9−1) Chemistry B (Twenty First Century Science)
J258/03 Breadth in Chemistry (Higher Tier)
Time allowed: 1 hour 45 minutes
You must have:
- a ruler (cm/mm)
- the Data Sheet for GCSE (9–1) Chemistry B (inside this document)
You can use:
- a scientific or graphical calculator
- an HB pencil
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
- Use black ink. You can use an HB pencil, but only for graphs and diagrams.
- Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
- Answer all the questions.
- Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
- The total mark for this paper is 90.
- The marks for each question are shown in brackets [ ].
- This document has 28 pages.
ADVICE
- Read each question carefully before you start your answer.
H
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1 A student investigates rate of reaction.
(a) The student does three experiments adding limestone to dilute hydrochloric acid.
In all three experiments, the student keeps these the same:
- the mass of limestone
- the volume of acid
- the concentration of acid.
In experiment 1 the student adds one large piece of limestone to the acid at 20 °C.
The student measures the volume of gas produced every 30 seconds.
Fig. 1.1 shows the results of experiment 1.
Fig. 1.
Volume of gas
produced (cm 3 ) 20
Time (s)
Calculate the rate of reaction during the first 120 seconds.
Use Fig. 1..
Give your answer to 2 decimal places.
Rate of reaction =................................................ cm 3 / s [3]
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(b) Table 1.1 shows the conditions used for all three experiments.
Table 1.
Type of limestone Temperature ( ° C)
Experiment 1 Large piece 20
Experiment 2 Large piece 40
Experiment 3 Powder 40
(i) Draw a line on Fig. 1.1 to show the expected results for experiment 2.
Use the information in Table 1.1 to help you. [2]
(ii) Experiment 3 is the fastest.
Explain why.
Use the information in Table 1..
Include ideas about collisions in your answer.
. ................................................................................................................................................. [2]
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F
Fluorine
2 Atoms contain protons, neutrons and electrons.
(a) The table shows the relative masses and relative charges of protons, neutrons and electrons.
Complete the table by filling in the blanks.
Particle Relative mass Relative charge
Electron 0.0005 – 1
[2]
(b) Fig. 2.1 shows information about fluorine.
Fig. 2.
Find the number of protons, neutrons and electrons in an atom of fluorine.
Protons = ...............................................................
Neutrons = ...............................................................
Electrons = ...............................................................
[3]
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(a) Iron reacts with oxygen in the presence of water to form hydrated iron oxide (rust).
(i) Complete the balanced symbol equation for the reaction.
4Fe(s) + 3..........(g) .......... Fe 2 O 3 (s)
[2]
(ii) This reaction can be called rusting.
What is another name for this reaction?
. ................................................................................................................................................. [1]
(b) Rusting can be prevented by sacrificial protection.
(i) Explain why zinc can be used as sacrificial protection for iron.
. ................................................................................................................................................. [2]
(ii) Which half equation shows the oxidation of zinc?
Tick (✓) one box.
Zn Zn 2+
Zn Zn 2+
Zn 2+
Zn 2+
[1]
(iii) What is meant by the term reduction?
. ................................................................................................................................................. [1]
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High melting point
Ions are arranged in a
regular lattice
Forms crystals Ions are free to move
Conducts electricity
when molten
Oppositely charged
ions are strongly
attracted to each other
(b) The properties of potassium bromide can be explained in terms of the behaviour of its ions.
Draw lines to connect each property with its correct explanation.
Property Explanation
[2]
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Heated with chlorine
Burns with a bright
yellow flame
Left in moist air Fizzes
Put in cold water Forms a white coating
5 The Periodic Table arranges the elements into groups.
(a) Group 1 of the Periodic Table contains reactive metals.
(i) Which statement about Group 1 metals is true?
Tick (✓) one box.
Group 1 metals are hard.
Potassium is the most reactive Group 1 metal.
Reactivity increases down the group.
[1]
(ii) Sodium is a Group 1 metal.
Sodium reacts with water, moist air and chlorine.
Draw lines to connect each reaction with its correct observation.
Reaction Observation
[2]
(iii) Caesium reacts with water to make hydrogen and one other product.
Complete the word equation for the reaction.
caesium + water hydrogen + .................................................................................................. [1]
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6 The Earth, including its atmosphere and its oceans, is made up from elements and compounds in
different states.
(a) The particle model can be used to describe the states of these substances and what happens to
the particles when they change state.
(i) Water, H 2 O, can be present on earth as a solid, liquid or gas.
Explain the changes in the movement and arrangement of particles when water changes from
liquid to solid.
. ................................................................................................................................................. [3]
(ii) State one limitation of the particle model.
. ................................................................................................................................................. [1]
(b) The greenhouse effect is an essential process for maintaining life on earth.
Carbon dioxide and methane cause the greenhouse effect.
(i) Which statements about greenhouse gases are true and which are false?
Tick (✓) one box in each row.
True False
They absorb infrared radiation from the Earth.
They come only from anthropogenic sources.
They emit radiation in all directions.
They prevent all radiation from the Sun passing through the atmosphere.
[3]
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(ii) Increased carbon dioxide and methane cause climate change.
State two possible consequences of climate change.
[2]
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(c) Some synthetic polymers are condensation polymers.
Which statements about condensation polymers are true and which are false?
Tick (✓) one box in each row.
True False
Condensation polymers contain repeating units.
Condensation polymers form from monomers that
contain two functional groups.
Some condensation polymers are hydrocarbons.
The polymer is the only product in a condensation
polymerisation reaction.
[3]
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8 A student investigates the law of conservation of mass.
(a) In one experiment, the student reacts sodium bicarbonate with dilute hydrochloric acid.
The equation shows the reaction.
NaHCO 3 (s) + HC l (aq) NaC l (aq) + H 2 O(l) + CO 2 (g)
Fig. 8.1 shows the apparatus the student uses at the start of the experiment.
Fig. 8.
Dilute HC l
Sodium bicarbonate
The mass of the flask and contents at the start of the experiment is 200.0 g.
(i) The student uses 40.0 g of dilute hydrochloric acid.
The empty conical flask weighs 150.0 g.
Calculate the number of moles of sodium bicarbonate the student adds to the flask at the start of
the reaction.
Number of moles =........................................................... [4]
Digital balance
200.0 g
