OCR
GCSE
Chemistry B
H033/02: Chemistry in depth
*1842260922*
AS 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 70.
• 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 16 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/5446/9] DC (ST/FC) 344562/5
OCR is an exempt Charity
Turn over
1 Catalytic converters on cars use metals such as platinum as heterogeneous catalysts.
Catalytic converters turn exhaust emissions such as carbon monoxide and nitrogen
monoxide into less hazardous products.
(a)
(i) Explain the meaning of the term heterogeneous here.
......................................................................................................................................
....................
, 2
......................................................................................................................................
............... [1]
(ii) Why is carbon monoxide hazardous?
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(iii) Write an equation for the reaction of carbon monoxide with nitrogen monoxide to give
less hazardous products.
[1]
(iv) A simple model to explain the function of a heterogeneous catalyst involves four
steps.
Complete Step 2 and Step 3 in the sequence below.
Step 1 Reactants are adsorbed onto the surface of the catalyst.
Step 2
...........................................................................................................................................
Step 3
...........................................................................................................................................
Step 4 Products are desorbed from the surface of the catalyst.
[1] (b)* Explain how a catalyst increases the rate of a reaction. Draw an energy
profile and a Boltzmann distribution.
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....................
© OCR 2025
, 3
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Extra answer space if required.
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2 Ethanol is an important alcohol that is made industrially by the hydration of ethene.
© OCR 2025 Turn over
, 4
(a) Give the conditions required for this industrial process.
......................................................................................................................................
....................
......................................................................................................................................
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......................................................................................................................................
............... [2]
(b) Ethanol can also be made in the laboratory by a two-step process as shown:
CH2=CH2 + H2SO4 CH3CH2OSO3H Step 1 CH3CH2OSO3H
+ H2O CH3CH2OH + H2SO4 Step 2
Write the overall equation for this two-step process.
[1]
(c) A student does the two-step process in part (b) using an alkene that is a liquid at
room temperature. The reaction is exothermic.
(i) The alkene has a boiling point of 30 °C and is highly flammable.
Suggest a practical arrangement that the student should use to avoid loss of the
alkene as a vapour.
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(ii) When the student has carried out both steps, a mixture is left. This mixture contains
an alcohol.
The student finds that drops of this mixture turn bromine water from brown to
colourless.
Suggest what this colour change tells the student about the conversion of the alkene
into alcohol.
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(d) Cyclopentene can be made into cyclopentanol using sulfuric acid.
© OCR 2025
GCSE
Chemistry B
H033/02: Chemistry in depth
*1842260922*
AS 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 70.
• 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 16 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/5446/9] DC (ST/FC) 344562/5
OCR is an exempt Charity
Turn over
1 Catalytic converters on cars use metals such as platinum as heterogeneous catalysts.
Catalytic converters turn exhaust emissions such as carbon monoxide and nitrogen
monoxide into less hazardous products.
(a)
(i) Explain the meaning of the term heterogeneous here.
......................................................................................................................................
....................
, 2
......................................................................................................................................
............... [1]
(ii) Why is carbon monoxide hazardous?
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(iii) Write an equation for the reaction of carbon monoxide with nitrogen monoxide to give
less hazardous products.
[1]
(iv) A simple model to explain the function of a heterogeneous catalyst involves four
steps.
Complete Step 2 and Step 3 in the sequence below.
Step 1 Reactants are adsorbed onto the surface of the catalyst.
Step 2
...........................................................................................................................................
Step 3
...........................................................................................................................................
Step 4 Products are desorbed from the surface of the catalyst.
[1] (b)* Explain how a catalyst increases the rate of a reaction. Draw an energy
profile and a Boltzmann distribution.
......................................................................................................................................
....................
© OCR 2025
, 3
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
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....................
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....................
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....................
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............. ...............................................................................................................................
...................... [6]
Extra answer space if required.
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
2 Ethanol is an important alcohol that is made industrially by the hydration of ethene.
© OCR 2025 Turn over
, 4
(a) Give the conditions required for this industrial process.
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
............... [2]
(b) Ethanol can also be made in the laboratory by a two-step process as shown:
CH2=CH2 + H2SO4 CH3CH2OSO3H Step 1 CH3CH2OSO3H
+ H2O CH3CH2OH + H2SO4 Step 2
Write the overall equation for this two-step process.
[1]
(c) A student does the two-step process in part (b) using an alkene that is a liquid at
room temperature. The reaction is exothermic.
(i) The alkene has a boiling point of 30 °C and is highly flammable.
Suggest a practical arrangement that the student should use to avoid loss of the
alkene as a vapour.
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(ii) When the student has carried out both steps, a mixture is left. This mixture contains
an alcohol.
The student finds that drops of this mixture turn bromine water from brown to
colourless.
Suggest what this colour change tells the student about the conversion of the alkene
into alcohol.
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(d) Cyclopentene can be made into cyclopentanol using sulfuric acid.
© OCR 2025
