A LEVEL CHEMISTRY A: Actual June 2025 PAST PAPER 1: Periodic table, elements and
physical chemistry. All Assessment Questions & Mark Scheme [OCR H432/01]
Exam Resource Summary
The A Level Chemistry A June 2025 Paper 1: Periodic Table, Elements and Physical
Chemistry (OCR H432/01) – All Assessment Questions & Mark Scheme combines the
complete official examination paper with its comprehensive mark scheme, creating an
invaluable resource for effective exam preparation. This paper assesses students’
knowledge and understanding of periodicity, structure and bonding, energetics,
redox reactions, and rates of reaction, as well as the physical and inorganic
chemistry concepts that underpin modern chemical science. It tests the ability to apply
theoretical principles, perform quantitative calculations, and interpret experimental data
with precision. The merged format presents each question alongside its marking criteria,
offering clear insight into examiner expectations, mark allocation, and response
structure. This resource is essential for targeted revision, self-assessment, and the
development of strong analytical and problem-solving skills, ensuring confident
preparation for the June 2026 OCR A Level Chemistry A Paper 1 and a solid foundation
for advanced chemistry studies.
Turn over
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1 The table shows the number of protons and neutrons in four different atoms.
Atom Number of protons Number of neutrons
W 17 18
X 18 18
Y 19 18
Z 18 19
Which two atoms are isotopes of the same element?
A W and X
B X and Y
C X and Z
D Y and Z
Your answer [1]
2 11.895 g of hydrated cobalt(II) chloride, CoCl 2•xH2O, is heated to remove the water of
crystallisation.
After heating to constant mass, the mass of the anhydrous salt was 6.495 g.
What is the value of x?
A 3
B 5
C 6
D 7
Your answer [1]
© OCR 2025
, 3
3 The diagram shows the Born-Haber cycle for sodium oxide, Na2O.
2Na+(g) + O2–(g)
2Na+(g) + O(g) + 2e–
2Na(g) + O(g)
2Na(g) + ½O2(g)
2Na(s) + ½O2(g)
Na2O(s)
Why is the value for the second electron affinity of oxygen positive?
A An electron is added to a high energy orbital.
B An electron is added to a negative ion.
C An electron is removed from a gaseous atom.
D An electron is removed from a positive ion.
Your answer [1]
4 What volume, in cm3, of 0.250 mol dm–3 barium hydroxide solution is required to exactly
neutralise 25.0 cm3 of 0.115 mol dm–3 hydrochloric acid?
Ba(OH)2(aq) + 2HCl (aq) BaCl 2(aq) + 2H2O(l)
A 5.75
B 11.50
C 23.00
D 54.35
Your answer [1]
© OCR 2025 Turn over
, 4
5 The graph shows the volume of hydrogen released over time in a chemical reaction.
100
90
80
70
60
Volume of
hydrogen 50
/ cm3
40
30
20
10
0
0 20 40 60 80 100
Time / s
What is the rate of reaction, in cm3 s–1, at 30 seconds?
A 0.8
B 1.2
C 2.1
D 2.4
Your answer [1]
© OCR 2025
physical chemistry. All Assessment Questions & Mark Scheme [OCR H432/01]
Exam Resource Summary
The A Level Chemistry A June 2025 Paper 1: Periodic Table, Elements and Physical
Chemistry (OCR H432/01) – All Assessment Questions & Mark Scheme combines the
complete official examination paper with its comprehensive mark scheme, creating an
invaluable resource for effective exam preparation. This paper assesses students’
knowledge and understanding of periodicity, structure and bonding, energetics,
redox reactions, and rates of reaction, as well as the physical and inorganic
chemistry concepts that underpin modern chemical science. It tests the ability to apply
theoretical principles, perform quantitative calculations, and interpret experimental data
with precision. The merged format presents each question alongside its marking criteria,
offering clear insight into examiner expectations, mark allocation, and response
structure. This resource is essential for targeted revision, self-assessment, and the
development of strong analytical and problem-solving skills, ensuring confident
preparation for the June 2026 OCR A Level Chemistry A Paper 1 and a solid foundation
for advanced chemistry studies.
Turn over
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1 The table shows the number of protons and neutrons in four different atoms.
Atom Number of protons Number of neutrons
W 17 18
X 18 18
Y 19 18
Z 18 19
Which two atoms are isotopes of the same element?
A W and X
B X and Y
C X and Z
D Y and Z
Your answer [1]
2 11.895 g of hydrated cobalt(II) chloride, CoCl 2•xH2O, is heated to remove the water of
crystallisation.
After heating to constant mass, the mass of the anhydrous salt was 6.495 g.
What is the value of x?
A 3
B 5
C 6
D 7
Your answer [1]
© OCR 2025
, 3
3 The diagram shows the Born-Haber cycle for sodium oxide, Na2O.
2Na+(g) + O2–(g)
2Na+(g) + O(g) + 2e–
2Na(g) + O(g)
2Na(g) + ½O2(g)
2Na(s) + ½O2(g)
Na2O(s)
Why is the value for the second electron affinity of oxygen positive?
A An electron is added to a high energy orbital.
B An electron is added to a negative ion.
C An electron is removed from a gaseous atom.
D An electron is removed from a positive ion.
Your answer [1]
4 What volume, in cm3, of 0.250 mol dm–3 barium hydroxide solution is required to exactly
neutralise 25.0 cm3 of 0.115 mol dm–3 hydrochloric acid?
Ba(OH)2(aq) + 2HCl (aq) BaCl 2(aq) + 2H2O(l)
A 5.75
B 11.50
C 23.00
D 54.35
Your answer [1]
© OCR 2025 Turn over
, 4
5 The graph shows the volume of hydrogen released over time in a chemical reaction.
100
90
80
70
60
Volume of
hydrogen 50
/ cm3
40
30
20
10
0
0 20 40 60 80 100
Time / s
What is the rate of reaction, in cm3 s–1, at 30 seconds?
A 0.8
B 1.2
C 2.1
D 2.4
Your answer [1]
© OCR 2025
