Centre Number
Candidate Number
General Certificate of Secondary Education
2025
GCSE Chemistry
Unit 2
Higher Tier
*GCM22*
[GCM22] *GCM22*
FRIDAY 13 JUNE, MORNING
TIME
1 hour 30 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces provided at the top of this
page.
You must answer the questions in the spaces provided.
Do not write outside the boxed area on each page or on blank pages.
Complete questions in black ink and use a dark HB pencil for drawings and graphs.
Do not write with a gel pen.
Answer all six questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 100.
Figures in brackets printed down the right-hand side of pages indicate the marks awarded to
each question or part question.
You may use a scientific calculator.
Quality of written communication will be assessed in Question 3(c).
A Data Leaflet, which includes a Periodic Table of the Elements, is included in this question
paper.
14544
*24GCM2201*
*24GCM2201*
, 1 (a) An experiment was set up to investigate the effect of four different solid catalysts
on the decomposition of hydrogen peroxide. A diagram of the apparatus used is
shown below. 25.0 cm3 of hydrogen peroxide solution and 1 g of solid catalyst
were used in the reaction and the time taken to produce 100 cm3 of gas was
recorded.
gas
gas syringe
hydrogen peroxide
solution
0:00:00
solid
catalyst
stopclock
Results of experiment
Solid catalyst Time taken to collect 100 cm3 of gas /s
A 120
B 35
C 11
D 54
14544
*24GCM2202*
*24GCM2202*
, (i) Name the products formed in the decomposition of hydrogen peroxide.
[1]
(ii) State and explain which solid (A, B, C or D) is the most effective catalyst.
[1]
(iii) Name one compound which could be used as a catalyst for the
decomposition of hydrogen peroxide.
[1]
(iv) In the first experiment, 1 g of solid A was used. Describe how it could be
shown experimentally at the end of the reaction that solid A was a catalyst
and not a reactant.
[3]
[Turn over
14544
*24GCM2203*
*24GCM2203*
, (b) The experiment was repeated using the same apparatus and the gas volume
collected was recorded at intervals of 20 seconds. Catalyst A was used.
The graph shows the results obtained.
110
100
90
80
70
Gas volume /cm3
60
50
40
30
20
10
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Time /s
(i) What volume of gas was produced in the first 10 seconds?
[1]
(ii) Describe fully how the gas volume produced changes with time.
[2]
14544
*24GCM2204*
*24GCM2204*
Candidate Number
General Certificate of Secondary Education
2025
GCSE Chemistry
Unit 2
Higher Tier
*GCM22*
[GCM22] *GCM22*
FRIDAY 13 JUNE, MORNING
TIME
1 hour 30 minutes.
INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces provided at the top of this
page.
You must answer the questions in the spaces provided.
Do not write outside the boxed area on each page or on blank pages.
Complete questions in black ink and use a dark HB pencil for drawings and graphs.
Do not write with a gel pen.
Answer all six questions.
INFORMATION FOR CANDIDATES
The total mark for this paper is 100.
Figures in brackets printed down the right-hand side of pages indicate the marks awarded to
each question or part question.
You may use a scientific calculator.
Quality of written communication will be assessed in Question 3(c).
A Data Leaflet, which includes a Periodic Table of the Elements, is included in this question
paper.
14544
*24GCM2201*
*24GCM2201*
, 1 (a) An experiment was set up to investigate the effect of four different solid catalysts
on the decomposition of hydrogen peroxide. A diagram of the apparatus used is
shown below. 25.0 cm3 of hydrogen peroxide solution and 1 g of solid catalyst
were used in the reaction and the time taken to produce 100 cm3 of gas was
recorded.
gas
gas syringe
hydrogen peroxide
solution
0:00:00
solid
catalyst
stopclock
Results of experiment
Solid catalyst Time taken to collect 100 cm3 of gas /s
A 120
B 35
C 11
D 54
14544
*24GCM2202*
*24GCM2202*
, (i) Name the products formed in the decomposition of hydrogen peroxide.
[1]
(ii) State and explain which solid (A, B, C or D) is the most effective catalyst.
[1]
(iii) Name one compound which could be used as a catalyst for the
decomposition of hydrogen peroxide.
[1]
(iv) In the first experiment, 1 g of solid A was used. Describe how it could be
shown experimentally at the end of the reaction that solid A was a catalyst
and not a reactant.
[3]
[Turn over
14544
*24GCM2203*
*24GCM2203*
, (b) The experiment was repeated using the same apparatus and the gas volume
collected was recorded at intervals of 20 seconds. Catalyst A was used.
The graph shows the results obtained.
110
100
90
80
70
Gas volume /cm3
60
50
40
30
20
10
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Time /s
(i) What volume of gas was produced in the first 10 seconds?
[1]
(ii) Describe fully how the gas volume produced changes with time.
[2]
14544
*24GCM2204*
*24GCM2204*
