OCR
GCSE
Chemistry A
H432/01: Periodic table, elements and physical chemistry
*1849435170*
A Level
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 page 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 100.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 32 pages.
ADVICE
• Read each question carefully before you start your answer
© OCR 2025 [601/5255/2] DC (PQ/SG) 347716/3
OCR is an exempt Charity
Turn over
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
, 2
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
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
3 The diagram shows the Born-Haber cycle for sodium oxide, Na2O.
2Na+(g) + O2–(g)
© OCR 2025
, 3
2Na + (g) + O(g) + 2e –
2Na(g) + O(g ) 2Na + (g) + O – (g) + e –
2Na(g) + ½O 2(g )
2Na(s) + ½O 2(g)
Na 2O(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
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
5 The graph shows the volume of hydrogen released over time in a chemical reaction.
© OCR 2025 Turn over
, 4
Volume
of
hydrogen
/ cm3
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
6 Methane reacts with oxygen as shown in the equation: CH4(g) + 2O2(g) CO2(g) +
2H2O(g) ΔrH = –730 kJ mol–1 The table shows some bond enthalpies.
Bond O–H O=O C=O
Bond enthalpy / kJ mol–1 +464 +498 +805
What is the bond enthalpy, in kJ mol , of the C–H bond in methane?
–1
A +109
B +367
C +435
D +568
Your answer
7 The table below shows the boiling points of some hydrogen halides.
Hydrogen halide Boiling point / K
© OCR 2025
GCSE
Chemistry A
H432/01: Periodic table, elements and physical chemistry
*1849435170*
A Level
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 page 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 100.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 32 pages.
ADVICE
• Read each question carefully before you start your answer
© OCR 2025 [601/5255/2] DC (PQ/SG) 347716/3
OCR is an exempt Charity
Turn over
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
, 2
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
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
3 The diagram shows the Born-Haber cycle for sodium oxide, Na2O.
2Na+(g) + O2–(g)
© OCR 2025
, 3
2Na + (g) + O(g) + 2e –
2Na(g) + O(g ) 2Na + (g) + O – (g) + e –
2Na(g) + ½O 2(g )
2Na(s) + ½O 2(g)
Na 2O(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
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
5 The graph shows the volume of hydrogen released over time in a chemical reaction.
© OCR 2025 Turn over
, 4
Volume
of
hydrogen
/ cm3
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
6 Methane reacts with oxygen as shown in the equation: CH4(g) + 2O2(g) CO2(g) +
2H2O(g) ΔrH = –730 kJ mol–1 The table shows some bond enthalpies.
Bond O–H O=O C=O
Bond enthalpy / kJ mol–1 +464 +498 +805
What is the bond enthalpy, in kJ mol , of the C–H bond in methane?
–1
A +109
B +367
C +435
D +568
Your answer
7 The table below shows the boiling points of some hydrogen halides.
Hydrogen halide Boiling point / K
© OCR 2025
