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KOJIUGYFCSCACPOCISC7TE2676272626
A-Level OCR 2025 Chemistry A Paper 3 Mark Scheme
IUHSYDDHASDGYG CCUSDCY DACiuyg;7ygjckjUIyaD;YGDIOIDDGDBA SDYDDIDYSDHKASUGSYG
GCE
Chemistry A
H432/03: Unified chemistry
A Level
Mark Scheme for June 2025
OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide
range of qualifications to meet the needs of candidates of all ages and abilities. OCR
qualifications include AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge
Technicals, Functional Skills, Key Skills, Entry Level qualifications, NVQs and vocational
qualifications in areas such as IT, business, languages, teaching/training, administration
and secretarial skills.
It is also responsible for developing new specifications to meet national requirements and
the needs of students and teachers. OCR is a not-for-profit organisation; any surplus
made is invested back into the establishment to help towards the development of
qualifications and support, which keep pace with the changing needs of today’s society.
This mark scheme is published as an aid to teachers and students, to indicate the
requirements of the examination. It shows the basis on which marks were awarded by
examiners. It does not indicate the details of the discussions which took place at an
examiners’ meeting before marking commenced.
All examiners are instructed that alternative correct answers and unexpected approaches
in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and
skills demonstrated.
Mark schemes should be read in conjunction with the published question papers and the
report on the examination.
© OCR 2025
Oxford Cambridge and RSA Examinations
,H432/03 Mark Scheme June 2025
MARKING INSTRUCTIONS
PREPARATION FOR MARKING
RM ASSESSOR
1. Make sure that you have accessed and completed the relevant training packages for on-screen marking: RM Assessor Online Training; OCR
Essential Guide to Marking.
2. Make sure that you have read and understood the mark scheme and the question paper for this unit.
3. Log-in to RM Assessor and mark the required number of practice responses (“scripts”) and the required number of standardisation
responses.
MARKING
1. Mark strictly to the mark scheme.
2. Marks awarded must relate directly to the marking criteria.
3. The schedule of dates is very important. It is essential that you meet the RM Assessor 50% and 100% (traditional 50% Batch 1 and 100%
Batch 2) deadlines. If you experience problems, you must contact your Team Leader (Supervisor) without delay.
4. If you are in any doubt about applying the mark scheme, consult your Team Leader by telephone, email or via the RM Assessor messaging
system
5. Crossed Out Responses
Where a candidate has crossed out a response and provided a clear alternative then the crossed out response is not marked. Where no
alternative response has been provided, examiners may give candidates the benefit of the doubt and mark the crossed out response where
legible.
, H432/03 Mark Scheme June 2025
Rubric Error Responses – Optional Questions
Where candidates have a choice of question across a whole paper or a whole section and have provided more answers than required, then all
responses are marked and the highest mark allowable within the rubric is given. Enter a mark for each question answered into RM assessor,
which will select the highest mark from those awarded. (The underlying assumption is that the candidate has penalised themselves by
attempting more questions than necessary in the time allowed.)
Multiple Choice Question Responses
When a multiple choice question has only a single, correct response and a candidate provides two responses (even if one of these responses
is correct), then no mark should be awarded (as it is not possible to determine which was the first response selected by the candidate).
When a question requires candidates to select more than one option/multiple options, then local marking arrangements need to ensure
consistency of approach.
Contradictory Responses
When a candidate provides contradictory responses, then no mark should be awarded, even if one of the answers is correct.
Short Answer Questions (requiring only a list by way of a response, usually worth only one mark per response)
Where candidates are required to provide a set number of short answer responses then only the set number of responses should be marked.
The response space should be marked from left to right on each line and then line by line until the required number of responses have been
considered. The remaining responses should not then be marked. Examiners will have to apply judgement as to whether a ‘second response’
on a line is a development of the ‘first response’, rather than a separate, discrete response. (The underlying assumption is that the candidate
is attempting to hedge their bets and therefore getting undue benefit rather than engaging with the question and giving the most relevant/correct
responses.)
Short Answer Questions (requiring a more developed response, worth two or more marks)
If the candidates are required to provide a description of, say, three items or factors and four items or factors are provided, then mark on a
similar basis – that is downwards (as it is unlikely in this situation that a candidate will provide more than one response in each section of the
response space.)
Longer Answer Questions (requiring a developed response)
Where candidates have provided two (or more) responses to a medium or high tariff question which only required a single (developed) response
and not crossed out the first response, then only the first response should be marked. Examiners will need to apply professional judgement as
to whether the second (or a subsequent) response is a ‘new start’ or simply a poorly expressed continuation of the first response.
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KOJIUGYFCSCACPOCISC7TE2676272626
A-Level OCR 2025 Chemistry A Paper 3 Mark Scheme
IUHSYDDHASDGYG CCUSDCY DACiuyg;7ygjckjUIyaD;YGDIOIDDGDBA SDYDDIDYSDHKASUGSYG
GCE
Chemistry A
H432/03: Unified chemistry
A Level
Mark Scheme for June 2025
OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide
range of qualifications to meet the needs of candidates of all ages and abilities. OCR
qualifications include AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge
Technicals, Functional Skills, Key Skills, Entry Level qualifications, NVQs and vocational
qualifications in areas such as IT, business, languages, teaching/training, administration
and secretarial skills.
It is also responsible for developing new specifications to meet national requirements and
the needs of students and teachers. OCR is a not-for-profit organisation; any surplus
made is invested back into the establishment to help towards the development of
qualifications and support, which keep pace with the changing needs of today’s society.
This mark scheme is published as an aid to teachers and students, to indicate the
requirements of the examination. It shows the basis on which marks were awarded by
examiners. It does not indicate the details of the discussions which took place at an
examiners’ meeting before marking commenced.
All examiners are instructed that alternative correct answers and unexpected approaches
in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and
skills demonstrated.
Mark schemes should be read in conjunction with the published question papers and the
report on the examination.
© OCR 2025
Oxford Cambridge and RSA Examinations
,H432/03 Mark Scheme June 2025
MARKING INSTRUCTIONS
PREPARATION FOR MARKING
RM ASSESSOR
1. Make sure that you have accessed and completed the relevant training packages for on-screen marking: RM Assessor Online Training; OCR
Essential Guide to Marking.
2. Make sure that you have read and understood the mark scheme and the question paper for this unit.
3. Log-in to RM Assessor and mark the required number of practice responses (“scripts”) and the required number of standardisation
responses.
MARKING
1. Mark strictly to the mark scheme.
2. Marks awarded must relate directly to the marking criteria.
3. The schedule of dates is very important. It is essential that you meet the RM Assessor 50% and 100% (traditional 50% Batch 1 and 100%
Batch 2) deadlines. If you experience problems, you must contact your Team Leader (Supervisor) without delay.
4. If you are in any doubt about applying the mark scheme, consult your Team Leader by telephone, email or via the RM Assessor messaging
system
5. Crossed Out Responses
Where a candidate has crossed out a response and provided a clear alternative then the crossed out response is not marked. Where no
alternative response has been provided, examiners may give candidates the benefit of the doubt and mark the crossed out response where
legible.
, H432/03 Mark Scheme June 2025
Rubric Error Responses – Optional Questions
Where candidates have a choice of question across a whole paper or a whole section and have provided more answers than required, then all
responses are marked and the highest mark allowable within the rubric is given. Enter a mark for each question answered into RM assessor,
which will select the highest mark from those awarded. (The underlying assumption is that the candidate has penalised themselves by
attempting more questions than necessary in the time allowed.)
Multiple Choice Question Responses
When a multiple choice question has only a single, correct response and a candidate provides two responses (even if one of these responses
is correct), then no mark should be awarded (as it is not possible to determine which was the first response selected by the candidate).
When a question requires candidates to select more than one option/multiple options, then local marking arrangements need to ensure
consistency of approach.
Contradictory Responses
When a candidate provides contradictory responses, then no mark should be awarded, even if one of the answers is correct.
Short Answer Questions (requiring only a list by way of a response, usually worth only one mark per response)
Where candidates are required to provide a set number of short answer responses then only the set number of responses should be marked.
The response space should be marked from left to right on each line and then line by line until the required number of responses have been
considered. The remaining responses should not then be marked. Examiners will have to apply judgement as to whether a ‘second response’
on a line is a development of the ‘first response’, rather than a separate, discrete response. (The underlying assumption is that the candidate
is attempting to hedge their bets and therefore getting undue benefit rather than engaging with the question and giving the most relevant/correct
responses.)
Short Answer Questions (requiring a more developed response, worth two or more marks)
If the candidates are required to provide a description of, say, three items or factors and four items or factors are provided, then mark on a
similar basis – that is downwards (as it is unlikely in this situation that a candidate will provide more than one response in each section of the
response space.)
Longer Answer Questions (requiring a developed response)
Where candidates have provided two (or more) responses to a medium or high tariff question which only required a single (developed) response
and not crossed out the first response, then only the first response should be marked. Examiners will need to apply professional judgement as
to whether the second (or a subsequent) response is a ‘new start’ or simply a poorly expressed continuation of the first response.
