worked solutions
model answers
, Oxford Cambridge and RSA
Friday 13 June 2025 – Morning
GCSE (9–1) Chemistry A (Gateway Science)
J248/04 (Higher Tier)
Time allowed: 1 hour 45 minutes
H
You must have:
* 1 8 5 9 5 2 2 8 4 6 *
• a ruler (cm/mm)
• the Data Sheet for GCSE (9–1) Chemistry A
(inside this document)
You can use:
• a scientific or graphical calculator
• an HB pencil
* J 2 4 8 0 4 *
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 page 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 28 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/8663/X] OCR is an exempt Charity
DC (PQ/CT) 353837/4 Turn over
for more: tyrionpapers.com
, 2
Section A
You should spend a maximum of 30 minutes on this section.
Write your answer to each question in the box provided.
1 Which row in the table shows the change in the percentage of each gas in the Earth’s
atmosphere today compared to the Earth’s early atmosphere?
Carbon dioxide Oxygen
A decreased decreased
B decreased increased
C increased decreased
D increased increased
Your answer [1]
© OCR 2025
for more: tyrionpapers.com
, 3
2 An iron nail is left in a test tube containing water.
Iron nail
Water
The iron nail rusts.
Which graph shows how the mass of the iron nail changes?
A
Mass
0
0 Time
B
Mass
0
0 Time
C
Mass
0
0 Time
D
Mass
0
0 Time
Your answer [1]
© OCR 2025 Turn over
for more: tyrionpapers.com
model answers
, Oxford Cambridge and RSA
Friday 13 June 2025 – Morning
GCSE (9–1) Chemistry A (Gateway Science)
J248/04 (Higher Tier)
Time allowed: 1 hour 45 minutes
H
You must have:
* 1 8 5 9 5 2 2 8 4 6 *
• a ruler (cm/mm)
• the Data Sheet for GCSE (9–1) Chemistry A
(inside this document)
You can use:
• a scientific or graphical calculator
• an HB pencil
* J 2 4 8 0 4 *
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 page 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 28 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/8663/X] OCR is an exempt Charity
DC (PQ/CT) 353837/4 Turn over
for more: tyrionpapers.com
, 2
Section A
You should spend a maximum of 30 minutes on this section.
Write your answer to each question in the box provided.
1 Which row in the table shows the change in the percentage of each gas in the Earth’s
atmosphere today compared to the Earth’s early atmosphere?
Carbon dioxide Oxygen
A decreased decreased
B decreased increased
C increased decreased
D increased increased
Your answer [1]
© OCR 2025
for more: tyrionpapers.com
, 3
2 An iron nail is left in a test tube containing water.
Iron nail
Water
The iron nail rusts.
Which graph shows how the mass of the iron nail changes?
A
Mass
0
0 Time
B
Mass
0
0 Time
C
Mass
0
0 Time
D
Mass
0
0 Time
Your answer [1]
© OCR 2025 Turn over
for more: tyrionpapers.com
