OCR A Level Chemistry B (Salters) Scientific
literacy in chemistry(H433/02) VERIFIED QP
AND MS
Oxford Cambridge and RSA
June 2026 – Morning
A Level Chemistry B (Salters)
H433/02 Scientific literacy in chemistry
Time allowed: 2 hours 15 minutes
You must have:
• a clean copy of the Advance Notice Article (inside
this document)
• the Data Sheet for Chemistry B
You can use:
• a scientific or graphical calculator
• an HB pencil
* H 4 3 3 0 2 *
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 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 20 pages.
ADVICE
• Read each question carefully before you start your answer.
,DC (PQ/CT) 344767/6
OCR is an
, exempt Charity
Turn over
*1850667802*
, 3
1 This question is about reactions of haloalkanes.
(a) CH3Cl is made by plants that grow on marshes.
If CH3Cl reaches the stratosphere, electromagnetic radiation causes it to undergo homolytic
fission forming chlorine radicals.
(i) Give the systematic name of CH3Cl .
. ................................................................................................................................................... [1]
(ii) Draw ‘half curly arrows’ to show the mechanism of the homolytic fission of CH3Cl .
Show the products of the reaction.
H
H C Cl
H
[2]
(iii) Which type of electromagnetic radiation causes this homolytic fission to occur in the stratosphere?
. ................................................................................................................................................... [1]
(iv) The bond energy of the C–Cl bond is 346 kJmol–1.
Calculate the wavelength (in m) of radiation which breaks this bond.
Give your answer to an appropriate number of significant figures.
Wavelength = ..................................................... m [5]
(v) Chlorine radicals catalyse the breakdown of ozone in the stratosphere.
Write equations to show how this occurs and give the overall equation.
Overall equation:
[2]
© OCR 2025 Turn over
literacy in chemistry(H433/02) VERIFIED QP
AND MS
Oxford Cambridge and RSA
June 2026 – Morning
A Level Chemistry B (Salters)
H433/02 Scientific literacy in chemistry
Time allowed: 2 hours 15 minutes
You must have:
• a clean copy of the Advance Notice Article (inside
this document)
• the Data Sheet for Chemistry B
You can use:
• a scientific or graphical calculator
• an HB pencil
* H 4 3 3 0 2 *
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 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 20 pages.
ADVICE
• Read each question carefully before you start your answer.
,DC (PQ/CT) 344767/6
OCR is an
, exempt Charity
Turn over
*1850667802*
, 3
1 This question is about reactions of haloalkanes.
(a) CH3Cl is made by plants that grow on marshes.
If CH3Cl reaches the stratosphere, electromagnetic radiation causes it to undergo homolytic
fission forming chlorine radicals.
(i) Give the systematic name of CH3Cl .
. ................................................................................................................................................... [1]
(ii) Draw ‘half curly arrows’ to show the mechanism of the homolytic fission of CH3Cl .
Show the products of the reaction.
H
H C Cl
H
[2]
(iii) Which type of electromagnetic radiation causes this homolytic fission to occur in the stratosphere?
. ................................................................................................................................................... [1]
(iv) The bond energy of the C–Cl bond is 346 kJmol–1.
Calculate the wavelength (in m) of radiation which breaks this bond.
Give your answer to an appropriate number of significant figures.
Wavelength = ..................................................... m [5]
(v) Chlorine radicals catalyse the breakdown of ozone in the stratosphere.
Write equations to show how this occurs and give the overall equation.
Overall equation:
[2]
© OCR 2025 Turn over
