Mark Scheme (Results)
Summer 2025
Pearson Edexcel GCSE
In Chemistry (1CH0)
Paper 2H
,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 P75509RRA
Publications Code 1CH0_2H_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 ma
• 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.
, Chemistry 1CH0_2H
Question Answer Mark
number
1(a) C Na+ is the only correct answer. (1)
AO1 2
A (brick red), B (green blue) and D (red) are not correct as these ions do not give a yellow flame. MCQ
Question Answer Mark
number
1(b)(i) C C7H5N3O6 is the only correct answer. (1)
AO2 1
A and B are incorrect as they have too few carbons; D is incorrect because it has too many hydrogens
Question Answer Additional Guidance Mark
number
1(b)(ii) (they are) explosive / can explode allow ‘blows up’ (1)
ignore other hazards such as toxic AO3-3
Summer 2025
Pearson Edexcel GCSE
In Chemistry (1CH0)
Paper 2H
,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 P75509RRA
Publications Code 1CH0_2H_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 ma
• 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.
, Chemistry 1CH0_2H
Question Answer Mark
number
1(a) C Na+ is the only correct answer. (1)
AO1 2
A (brick red), B (green blue) and D (red) are not correct as these ions do not give a yellow flame. MCQ
Question Answer Mark
number
1(b)(i) C C7H5N3O6 is the only correct answer. (1)
AO2 1
A and B are incorrect as they have too few carbons; D is incorrect because it has too many hydrogens
Question Answer Additional Guidance Mark
number
1(b)(ii) (they are) explosive / can explode allow ‘blows up’ (1)
ignore other hazards such as toxic AO3-3
