GCSE CHEMISTRY A (GATEWAY SCIENCE) — Actual June 2025 PAST PAPER: Chemistry A
(Higher Tier). All Assessment Questions & Mark Scheme [OCR J248/04]
Exam Resource Summary
The GCSE (9–1) Chemistry A (Gateway Science) June 2025 Higher Tier Paper (OCR J248/04) integrates
the full official examination paper with its detailed mark scheme to create a complete and focused
revision resource. This paper assesses students’ understanding of advanced chemical concepts including
atomic structure, bonding, chemical reactions, energetics, kinetics, organic chemistry, the periodic table,
and practical investigation skills. Candidates are required to apply knowledge to unfamiliar contexts,
interpret and analyse data, evaluate experimental methods, and construct coherent, evidence-based
scientific explanations. By presenting each question alongside its marking guidance, this merged resource
clarifies examiner expectations, demonstrates the analytical and evaluative skills needed for high-band
marks, and supports the development of structured, accurate, and well-reasoned responses. This integrated
format strengthens revision efficiency, enhances exam technique, and prepares students thoroughly for the
2026 OCR GCSE Chemistry A (Gateway Science) Higher Tier examination.
OCR is an exempt Charity
Turn over
, 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
, 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
, 4
3 The alkanes are a homologous series of molecules.
Which statement about different alkane molecules is correct?
A The molecular formula of the molecules differs by CH3.
B The molecules all contain a double bond.
C The molecules all have the same general formula.
D The molecules all have the same physical properties.
Your answer [1]
4 Which row in the table shows a property of a Group 1 metal and of a transition metal?
Group 1 metal Transition metal
A forms white compounds low density
B high melting point conducts electricity
C low density forms coloured compounds
D very reactive low density
Your answer [1]
5 The theoretical yield of a product in a reaction is 71 g.
The actual yield is 60 g.
What is the percentage yield?
A 15.5%
B 18.3%
C 84.5%
D 118.3%
Your answer [1]
© OCR 2025
(Higher Tier). All Assessment Questions & Mark Scheme [OCR J248/04]
Exam Resource Summary
The GCSE (9–1) Chemistry A (Gateway Science) June 2025 Higher Tier Paper (OCR J248/04) integrates
the full official examination paper with its detailed mark scheme to create a complete and focused
revision resource. This paper assesses students’ understanding of advanced chemical concepts including
atomic structure, bonding, chemical reactions, energetics, kinetics, organic chemistry, the periodic table,
and practical investigation skills. Candidates are required to apply knowledge to unfamiliar contexts,
interpret and analyse data, evaluate experimental methods, and construct coherent, evidence-based
scientific explanations. By presenting each question alongside its marking guidance, this merged resource
clarifies examiner expectations, demonstrates the analytical and evaluative skills needed for high-band
marks, and supports the development of structured, accurate, and well-reasoned responses. This integrated
format strengthens revision efficiency, enhances exam technique, and prepares students thoroughly for the
2026 OCR GCSE Chemistry A (Gateway Science) Higher Tier examination.
OCR is an exempt Charity
Turn over
, 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
, 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
, 4
3 The alkanes are a homologous series of molecules.
Which statement about different alkane molecules is correct?
A The molecular formula of the molecules differs by CH3.
B The molecules all contain a double bond.
C The molecules all have the same general formula.
D The molecules all have the same physical properties.
Your answer [1]
4 Which row in the table shows a property of a Group 1 metal and of a transition metal?
Group 1 metal Transition metal
A forms white compounds low density
B high melting point conducts electricity
C low density forms coloured compounds
D very reactive low density
Your answer [1]
5 The theoretical yield of a product in a reaction is 71 g.
The actual yield is 60 g.
What is the percentage yield?
A 15.5%
B 18.3%
C 84.5%
D 118.3%
Your answer [1]
© OCR 2025
