GCSE CHEMISTRY B (TWENTY FIRST CENTURY SCIENCE) — Actual June 2025 PAST
PAPER: Depth in Chemistry (Higher Tier). All Assessment Questions & Mark Scheme [OCR
J258/04]
Exam Resource Summary
The GCSE (9–1) Chemistry B (Twenty First Century Science) June 2025 Higher Tier Paper (OCR
J258/04) combines the full official examination paper with its detailed mark scheme to provide a
comprehensive and exam-focused revision resource. This paper assesses students’ understanding of
specific chemical topics in depth, including atomic structure, bonding, chemical reactions, energetics,
rates of reaction, organic chemistry, the periodic table, and practical investigation skills. Candidates are
expected to apply knowledge to unfamiliar scenarios, analyse and interpret data, evaluate evidence, and
construct well-reasoned, scientifically accurate explanations. By presenting each question alongside the
marking criteria, this merged resource clarifies examiner expectations, highlights the analytical and
evaluative skills required for high marks, and guides learners in producing structured, precise, and
complete responses. This integrated format supports effective revision, strengthens exam technique, and
prepares students thoroughly for the 2026 OCR GCSE Chemistry B (Twenty First Century Science)
Higher Tier Depth in Chemistry examination.
OCR is an exempt Charity
Turn over
, 2
1 Potassium, sodium and lithium are metals in Group 1 of the Periodic Table.
A student watches a video of the reaction of potassium with water.
Fig. 1.1 shows a diagram of the experiment.
Fig. 1.1
Water Potassium
The table shows information about this reaction.
Metal Products of the reaction Observations
Potassium Potassium hydroxide Potassium moves quickly on the surface of the
water and fizzes violently.
Hydrogen gas
Potassium burns with a pale purple flame.
(a) The student then watches a video of the reaction of sodium with water.
Predict the products of the reaction of sodium with water and describe the observations you
expect.
Products ................................................................. and .................................................................
Observations ....................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
[3]
© OCR 2025
, 3
(b) Fig. 1.2 shows the arrangement of electrons in a lithium atom and a fluorine atom.
Fig. 1.2
Lithium atom Fluorine atom
Li F
(i) Lithium and fluorine belong to different groups of the Periodic Table.
Explain how the arrangement of electrons in lithium and fluorine is related to their groups in the
Periodic Table.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ................................................................................................................................................. [2]
(ii) Explain how Fig. 1.2 shows that lithium and fluorine are in the same period of the Periodic Table.
..........................................................................................................................................................
. ................................................................................................................................................. [1]
© OCR 2025 Turn over
,
PAPER: Depth in Chemistry (Higher Tier). All Assessment Questions & Mark Scheme [OCR
J258/04]
Exam Resource Summary
The GCSE (9–1) Chemistry B (Twenty First Century Science) June 2025 Higher Tier Paper (OCR
J258/04) combines the full official examination paper with its detailed mark scheme to provide a
comprehensive and exam-focused revision resource. This paper assesses students’ understanding of
specific chemical topics in depth, including atomic structure, bonding, chemical reactions, energetics,
rates of reaction, organic chemistry, the periodic table, and practical investigation skills. Candidates are
expected to apply knowledge to unfamiliar scenarios, analyse and interpret data, evaluate evidence, and
construct well-reasoned, scientifically accurate explanations. By presenting each question alongside the
marking criteria, this merged resource clarifies examiner expectations, highlights the analytical and
evaluative skills required for high marks, and guides learners in producing structured, precise, and
complete responses. This integrated format supports effective revision, strengthens exam technique, and
prepares students thoroughly for the 2026 OCR GCSE Chemistry B (Twenty First Century Science)
Higher Tier Depth in Chemistry examination.
OCR is an exempt Charity
Turn over
, 2
1 Potassium, sodium and lithium are metals in Group 1 of the Periodic Table.
A student watches a video of the reaction of potassium with water.
Fig. 1.1 shows a diagram of the experiment.
Fig. 1.1
Water Potassium
The table shows information about this reaction.
Metal Products of the reaction Observations
Potassium Potassium hydroxide Potassium moves quickly on the surface of the
water and fizzes violently.
Hydrogen gas
Potassium burns with a pale purple flame.
(a) The student then watches a video of the reaction of sodium with water.
Predict the products of the reaction of sodium with water and describe the observations you
expect.
Products ................................................................. and .................................................................
Observations ....................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
[3]
© OCR 2025
, 3
(b) Fig. 1.2 shows the arrangement of electrons in a lithium atom and a fluorine atom.
Fig. 1.2
Lithium atom Fluorine atom
Li F
(i) Lithium and fluorine belong to different groups of the Periodic Table.
Explain how the arrangement of electrons in lithium and fluorine is related to their groups in the
Periodic Table.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ................................................................................................................................................. [2]
(ii) Explain how Fig. 1.2 shows that lithium and fluorine are in the same period of the Periodic Table.
..........................................................................................................................................................
. ................................................................................................................................................. [1]
© OCR 2025 Turn over
,
