OCR SUMMER 2026
PREDICTED PAPER
GCSE (9–1) Chemistry B (Twenty First Century Science)
J258/04 Depth 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
H
• 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 [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 21 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
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, 2
1. A student investigates the rate of reaction between marble chips (calcium carbonate) and
hydrochloric acid. The student measures the volume of carbon dioxide gas produced over time.
The graph shows two curves levelling off at different final volumes — line A levels off at about 82
cm³, while line B levels off at about 80 cm³.
(a) State the total volume of gas produced by line B when the reaction is complete.
volume of gas......................................................................................................... [1]
(b) The student draws a tangent to the curve at time = 40 s.
The tangent passes through the coordinates (0, 30) and (72, 90).
Using the graph, calculate the rate of reaction at t = 40 seconds for the steeper curve.
Show your working.
Rate = ................................ cm³/s [2]
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, 3
(c) The student repeats the experiment using the same mass of marble chips but cuts
them into smaller pieces. Explain, in terms of surface area and particle collisions,
why the rate of reaction increases.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
................................................................................................................................... [3]
(d) (i) The student adds a catalyst to the original reaction. State what is meant by a catalyst.
...................................................................................................................................
...................................................................................................................................
................................................................................................................................... [1]
(ii) Explain how a catalyst increases the rate of reaction in terms of activation energy.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
................................................................................................................................... [2]
for more: tyrionpapers.com
PREDICTED PAPER
GCSE (9–1) Chemistry B (Twenty First Century Science)
J258/04 Depth 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
H
• 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 [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 21 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
for more: tyrionpapers.com
, 2
1. A student investigates the rate of reaction between marble chips (calcium carbonate) and
hydrochloric acid. The student measures the volume of carbon dioxide gas produced over time.
The graph shows two curves levelling off at different final volumes — line A levels off at about 82
cm³, while line B levels off at about 80 cm³.
(a) State the total volume of gas produced by line B when the reaction is complete.
volume of gas......................................................................................................... [1]
(b) The student draws a tangent to the curve at time = 40 s.
The tangent passes through the coordinates (0, 30) and (72, 90).
Using the graph, calculate the rate of reaction at t = 40 seconds for the steeper curve.
Show your working.
Rate = ................................ cm³/s [2]
for more: tyrionpapers.com
, 3
(c) The student repeats the experiment using the same mass of marble chips but cuts
them into smaller pieces. Explain, in terms of surface area and particle collisions,
why the rate of reaction increases.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
................................................................................................................................... [3]
(d) (i) The student adds a catalyst to the original reaction. State what is meant by a catalyst.
...................................................................................................................................
...................................................................................................................................
................................................................................................................................... [1]
(ii) Explain how a catalyst increases the rate of reaction in terms of activation energy.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
................................................................................................................................... [2]
for more: tyrionpapers.com
