GCSE
Chemistry A
H032/01: Breadth in chemistry
AS Level
*1442536263*
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 70.
• The marks for each question are shown in brackets [ ].
• This document has 24 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/5256/4] DC (CJ/CT) 346053/4
OCR is an exempt Charity
Turn over
SECTION A
You should spend a maximum of 25 minutes on this
section.
Write your answer to each question in the box provided.
1 The burette readings from a titration are shown below.
Initial reading / cm3 4.95
Final reading / cm3 23.10
The burette used has an uncertainty of 0.05 cm3 for each reading.
What is the percentage uncertainty of the resulting titre?
A 0.22%
, 2
B 0.28%
C 0.44%
D 0.55%
Your answer
2 How many p electrons does an atom of chlorine have?
A 5
B 7
C 11
D 17
Your answer
3 What is the number of hydrogen atoms in 6.8 g NH3?
A 2.408 × 1023
B 3.612 × 1023
C 7.224 × 1023
D 1.806 × 1024
Your answer [1] 4 Which reaction to extract iron (Fe) has the highest
atom economy?
A 2Al + Fe2O 2Fe + Al 2O3
3
B FeO + CO Fe + CO2
C Fe2O3 + 3CO 2Fe + 3CO2
D 2Fe2O3 + 3C 4Fe + 3CO2
Your answer
5 Phosphorus is burnt in oxygen to produce a mixture of oxides.
Which oxide has the closest to 50% by mass of phosphorus?
© OCR 2025
, 3
A PO2
B P2O3
C P2O5
D P4O9
Your answer
6 What is the oxidation number of S in Na2S2O3?
A –4
B –2
C +2
D +4
Your answer
7 Which of the following is not a redox reaction?
A CH4(g) + 2O2(g) CO2(g) + 2H2O(l)
B NaOH(aq) + HCl (aq) NaCl (aq) + H2O(l)
C 2KCl O3(s) 2KCl (s) + 3O2(g)
D Fe(s) + 4 H2SO (aq) FeSO4(aq) + H2(g)
Your answer [1] 8 Which compound has molecules with
a trigonal planar shape?
A BeCl 2
B BCl 3
C
© OCR 2025 Turn over
, 4
Your answer
9 Which equation describes the second ionisation energy of magnesium?
2+
A Mg Mg(g) (g) + 2e–
B Mg2+ Mg(s) (g) + 2e–
C Mg Mg2+ +
(g) (g) + e–
–
D Mg (g) + e 2+
Mg+(g)
Your answer
10 Which molecule is polar?
A H2S
B CO2
C CCl4
D C2F4
Your answer [1] 11 The equation for the complete combustion of
methanol, CH3OH, is shown below.
CH3OH(l) + 1 O2(g) CO2(g) + 2H2O(l)
The table shows standard enthalpy changes of formation, Δf Ho, in kJ mol–1.
Substance CH3OH(l) O2(g) CO2(g) H2O(l)
Δ H o / kJ mol–1 –239 0 –393 –286
f
What is the enthalpy change of combustion of CH3OH(l), in kJ mol ? –1
A +726
B +440
C – 440
D –726
Your answer
12 Hydrogen and iodine react in the reaction below.
© OCR 2025
Chemistry A
H032/01: Breadth in chemistry
AS Level
*1442536263*
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 70.
• The marks for each question are shown in brackets [ ].
• This document has 24 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/5256/4] DC (CJ/CT) 346053/4
OCR is an exempt Charity
Turn over
SECTION A
You should spend a maximum of 25 minutes on this
section.
Write your answer to each question in the box provided.
1 The burette readings from a titration are shown below.
Initial reading / cm3 4.95
Final reading / cm3 23.10
The burette used has an uncertainty of 0.05 cm3 for each reading.
What is the percentage uncertainty of the resulting titre?
A 0.22%
, 2
B 0.28%
C 0.44%
D 0.55%
Your answer
2 How many p electrons does an atom of chlorine have?
A 5
B 7
C 11
D 17
Your answer
3 What is the number of hydrogen atoms in 6.8 g NH3?
A 2.408 × 1023
B 3.612 × 1023
C 7.224 × 1023
D 1.806 × 1024
Your answer [1] 4 Which reaction to extract iron (Fe) has the highest
atom economy?
A 2Al + Fe2O 2Fe + Al 2O3
3
B FeO + CO Fe + CO2
C Fe2O3 + 3CO 2Fe + 3CO2
D 2Fe2O3 + 3C 4Fe + 3CO2
Your answer
5 Phosphorus is burnt in oxygen to produce a mixture of oxides.
Which oxide has the closest to 50% by mass of phosphorus?
© OCR 2025
, 3
A PO2
B P2O3
C P2O5
D P4O9
Your answer
6 What is the oxidation number of S in Na2S2O3?
A –4
B –2
C +2
D +4
Your answer
7 Which of the following is not a redox reaction?
A CH4(g) + 2O2(g) CO2(g) + 2H2O(l)
B NaOH(aq) + HCl (aq) NaCl (aq) + H2O(l)
C 2KCl O3(s) 2KCl (s) + 3O2(g)
D Fe(s) + 4 H2SO (aq) FeSO4(aq) + H2(g)
Your answer [1] 8 Which compound has molecules with
a trigonal planar shape?
A BeCl 2
B BCl 3
C
© OCR 2025 Turn over
, 4
Your answer
9 Which equation describes the second ionisation energy of magnesium?
2+
A Mg Mg(g) (g) + 2e–
B Mg2+ Mg(s) (g) + 2e–
C Mg Mg2+ +
(g) (g) + e–
–
D Mg (g) + e 2+
Mg+(g)
Your answer
10 Which molecule is polar?
A H2S
B CO2
C CCl4
D C2F4
Your answer [1] 11 The equation for the complete combustion of
methanol, CH3OH, is shown below.
CH3OH(l) + 1 O2(g) CO2(g) + 2H2O(l)
The table shows standard enthalpy changes of formation, Δf Ho, in kJ mol–1.
Substance CH3OH(l) O2(g) CO2(g) H2O(l)
Δ H o / kJ mol–1 –239 0 –393 –286
f
What is the enthalpy change of combustion of CH3OH(l), in kJ mol ? –1
A +726
B +440
C – 440
D –726
Your answer
12 Hydrogen and iodine react in the reaction below.
© OCR 2025
