2O25 OCR AS Level Chemistry A H032/01
Breadth in chemistry
Verified Question paper with Marking
Scheme combined
INSTRUCTIONS
Candidate number
• 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.
OCR AS LEVEL INFORMATION
• The total mark for this paper is 70.
CHEMISTRY A • The marks for each question are shown
in brackets [ ].
• This document has 24 pages.
ADVICE
• Read each question carefully before you
start your answer
, Oxford Cambridge and RSA
Tuesday 13 May 2025 – Morning
AS Level Chemistry A
H032/01 Breadth in chemistry
Time allowed: 1 hour 30 minutes
You must have:
• the Data Sheet for Chemistry A
You can use:
• a scientific or graphical calculator
• an HB penc*
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
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] OCR is an exempt Charity
DC (CJ/CT) 346053/4 Turn over
, 2
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.
3
Initial reading / cm 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%
B 0.28%
C 0.44%
D 0.55%
Your answer [1]
2 How many p electrons does an atom of chlorine have? A 5
B7C
11 D 17
Your answer [1]
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]
© OCR 2025
, 3
4 Which reaction to extract iron (Fe) has the highest atom economy?
A 2Al + Fe2O3 2Fe + Al 2O3 B
FeO + CO Fe + CO2
C Fe2O3 + 3CO 2Fe + 3CO2
D 2Fe2O3 + 3C 4Fe + 3CO2
Your answer [1]
5 Phosphorus is burnt in oxygen to produce a mixture of oxides.
Which oxide has the closest to 50% by mass of phosphorus?
A PO2 B
P2O3 C
P2O5 D
P4O9
Your answer [1]
6 What is the oxidation number of S in Na2S2O3? A –
4
B –2 C
+2 D +4
Your answer [1]
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) + H2SO4(aq) FeSO4(aq) + H2(g)
Your answer [1]
© OCR 2025 Turn over
Breadth in chemistry
Verified Question paper with Marking
Scheme combined
INSTRUCTIONS
Candidate number
• 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.
OCR AS LEVEL INFORMATION
• The total mark for this paper is 70.
CHEMISTRY A • The marks for each question are shown
in brackets [ ].
• This document has 24 pages.
ADVICE
• Read each question carefully before you
start your answer
, Oxford Cambridge and RSA
Tuesday 13 May 2025 – Morning
AS Level Chemistry A
H032/01 Breadth in chemistry
Time allowed: 1 hour 30 minutes
You must have:
• the Data Sheet for Chemistry A
You can use:
• a scientific or graphical calculator
• an HB penc*
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
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] OCR is an exempt Charity
DC (CJ/CT) 346053/4 Turn over
, 2
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.
3
Initial reading / cm 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%
B 0.28%
C 0.44%
D 0.55%
Your answer [1]
2 How many p electrons does an atom of chlorine have? A 5
B7C
11 D 17
Your answer [1]
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]
© OCR 2025
, 3
4 Which reaction to extract iron (Fe) has the highest atom economy?
A 2Al + Fe2O3 2Fe + Al 2O3 B
FeO + CO Fe + CO2
C Fe2O3 + 3CO 2Fe + 3CO2
D 2Fe2O3 + 3C 4Fe + 3CO2
Your answer [1]
5 Phosphorus is burnt in oxygen to produce a mixture of oxides.
Which oxide has the closest to 50% by mass of phosphorus?
A PO2 B
P2O3 C
P2O5 D
P4O9
Your answer [1]
6 What is the oxidation number of S in Na2S2O3? A –
4
B –2 C
+2 D +4
Your answer [1]
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) + H2SO4(aq) FeSO4(aq) + H2(g)
Your answer [1]
© OCR 2025 Turn over
