Mark Scheme (Results)
Summer 2025
Pearson Edexcel International Advanced Level
In Chemistry (WCH15)
Paper 01 Transition Metals and Organic Nitrogen
Chemistry
,Edexcel and BTEC Qualifications
Edexcel and BTEC qualifications are awarded by Pearson, the UK’s largest awarding body. We
provide a wide range of qualifications including academic, vocational, occupational and specific
programmes for employers. For further information visit our qualifications websites at
www.edexcel.com or www.btec.co.uk. Alternatively, you can get in touch with us using the details
on our contact us page at www.edexcel.com/contactus.
Pearson: helping people progress, everywhere
Pearson aspires to be the world’s leading learning company. Our aim is to help everyone progress
in their lives through education. We believe in every kind of learning, for all kinds of people,
wherever they are in the world. We’ve been involved in education for over 150 years, and by
working across 70 countries, in 100 languages, we have built an international reputation for our
commitment to high standards and raising achievement through innovation in education. Find out
more about how we can help you and your students at: www.pearson.com/uk
Summer 2025
Question Paper Log Number P78746A
Publications Code WCH15_01_2506_MS
All the material in this publication is copyright
© Pearson Education Ltd 2025
,General Marking Guidance
• All candidates must receive the same treatment. Examiners
must mark the first candidate in exactly the same way as they
mark the last.
• Mark schemes should be applied positively. Candidates must be
rewarded for what they have shown they can do rather than
penalised for omissions.
• Examiners should mark according to the mark scheme not
according to their perception of where the grade boundaries
may lie.
• There is no ceiling on achievement. All marks on the mark
scheme should be used appropriately.
• All the marks on the mark scheme are designed to be awarded.
Examiners should always award full marks if deserved, i.e. if the
answer matches the mark scheme. Examiners should also be
prepared to award zero marks if the candidate’s response is not
worthy of credit according to the mark scheme.
• Where some judgement is required, mark schemes will provide
the principles by which marks will be awarded and
exemplification may be limited.
• When examiners are in doubt regarding the application of the
mark scheme to a candidate’s response, the team leader must
be consulted.
• Crossed out work should be marked UNLESS the candidate has
replaced it with an alternative response.
, Using the Mark Scheme
Examiners should look for qualities to reward rather than faults to penalise. This does
NOT mean giving credit for incorrect or inadequate answers, but it does mean
allowing candidates to be rewarded for answers showing correct application of
principles and knowledge. Examiners should therefore read carefully and consider
every response: even if it is not what is expected it may be worthy of credit.
The mark scheme gives examiners:
• an idea of the types of response expected
• how individual marks are to be awarded
• the total mark for each question
• examples of responses that should NOT receive credit.
/ means that the responses are alternatives and either answer should receive full
credit.
( ) means that a phrase/word is not essential for the award of the mark, but helps the
examiner to get the sense of the expected answer.
Phrases/words in bold indicate that the meaning of the phrase or the actual word is
essential to the answer.
ecf/TE/cq (error carried forward) means that a wrong answer given in an earlier part
of a question is used correctly in answer to a later part of the same question.
Candidates must make their meaning clear to the examiner to gain the mark. Make
sure that the answer makes sense. Do not give credit for correct words/phrases which
are put together in a meaningless manner. Answers must be in the correct context.
Quality of Written Communication
Questions which involve the writing of continuous prose will expect candidates to:
• write legibly, with accurate use of spelling, grammar and punctuation in order to
make the meaning clear
• select and use a form and style of writing appropriate to purpose and to complex
subject matter
• organise information clearly and coherently, using specialist vocabulary when
appropriate.
Full marks will be awarded if the candidate has demonstrated the above abilities.
Questions where QWC is likely to be particularly important are indicated (QWC) in the
mark scheme, but this does not preclude others.
Summer 2025
Pearson Edexcel International Advanced Level
In Chemistry (WCH15)
Paper 01 Transition Metals and Organic Nitrogen
Chemistry
,Edexcel and BTEC Qualifications
Edexcel and BTEC qualifications are awarded by Pearson, the UK’s largest awarding body. We
provide a wide range of qualifications including academic, vocational, occupational and specific
programmes for employers. For further information visit our qualifications websites at
www.edexcel.com or www.btec.co.uk. Alternatively, you can get in touch with us using the details
on our contact us page at www.edexcel.com/contactus.
Pearson: helping people progress, everywhere
Pearson aspires to be the world’s leading learning company. Our aim is to help everyone progress
in their lives through education. We believe in every kind of learning, for all kinds of people,
wherever they are in the world. We’ve been involved in education for over 150 years, and by
working across 70 countries, in 100 languages, we have built an international reputation for our
commitment to high standards and raising achievement through innovation in education. Find out
more about how we can help you and your students at: www.pearson.com/uk
Summer 2025
Question Paper Log Number P78746A
Publications Code WCH15_01_2506_MS
All the material in this publication is copyright
© Pearson Education Ltd 2025
,General Marking Guidance
• All candidates must receive the same treatment. Examiners
must mark the first candidate in exactly the same way as they
mark the last.
• Mark schemes should be applied positively. Candidates must be
rewarded for what they have shown they can do rather than
penalised for omissions.
• Examiners should mark according to the mark scheme not
according to their perception of where the grade boundaries
may lie.
• There is no ceiling on achievement. All marks on the mark
scheme should be used appropriately.
• All the marks on the mark scheme are designed to be awarded.
Examiners should always award full marks if deserved, i.e. if the
answer matches the mark scheme. Examiners should also be
prepared to award zero marks if the candidate’s response is not
worthy of credit according to the mark scheme.
• Where some judgement is required, mark schemes will provide
the principles by which marks will be awarded and
exemplification may be limited.
• When examiners are in doubt regarding the application of the
mark scheme to a candidate’s response, the team leader must
be consulted.
• Crossed out work should be marked UNLESS the candidate has
replaced it with an alternative response.
, Using the Mark Scheme
Examiners should look for qualities to reward rather than faults to penalise. This does
NOT mean giving credit for incorrect or inadequate answers, but it does mean
allowing candidates to be rewarded for answers showing correct application of
principles and knowledge. Examiners should therefore read carefully and consider
every response: even if it is not what is expected it may be worthy of credit.
The mark scheme gives examiners:
• an idea of the types of response expected
• how individual marks are to be awarded
• the total mark for each question
• examples of responses that should NOT receive credit.
/ means that the responses are alternatives and either answer should receive full
credit.
( ) means that a phrase/word is not essential for the award of the mark, but helps the
examiner to get the sense of the expected answer.
Phrases/words in bold indicate that the meaning of the phrase or the actual word is
essential to the answer.
ecf/TE/cq (error carried forward) means that a wrong answer given in an earlier part
of a question is used correctly in answer to a later part of the same question.
Candidates must make their meaning clear to the examiner to gain the mark. Make
sure that the answer makes sense. Do not give credit for correct words/phrases which
are put together in a meaningless manner. Answers must be in the correct context.
Quality of Written Communication
Questions which involve the writing of continuous prose will expect candidates to:
• write legibly, with accurate use of spelling, grammar and punctuation in order to
make the meaning clear
• select and use a form and style of writing appropriate to purpose and to complex
subject matter
• organise information clearly and coherently, using specialist vocabulary when
appropriate.
Full marks will be awarded if the candidate has demonstrated the above abilities.
Questions where QWC is likely to be particularly important are indicated (QWC) in the
mark scheme, but this does not preclude others.
