Pearson Edexcel International Advanced Level
Wednesday 6 May 2026
WCH11/01A
Paper
Afternoon (Time: 1 hour 30 minutes)
reference
Chemistry
International Advanced Subsidiary/Advanced Level
UNIT 1: Structure, Bonding and Introduction to Mark Scheme (Results)
Organic Chemistry
Question Paper
You must have:
Scientific calculator, ruler and Answer Book (sent separately)
Summer 2026
Pearson Edexcel International Advanced
Subsidiary Level In Chemistry
WCH11/01A
Turn over
P81804APearson Education Ltd.
P:1/1/1/1/1/1
*P81804A*
, SECTION A Edexcel and BTEC Qualifications
Answer ALL the questions in this section in the Answer Book.
You should aim to spend no more than 20 minutes on this section.
Edexcel and BTEC qualifications are awarded by Pearson, the UK’s
For each question, select one answer from A to D and put a cross in the box in the
largest awarding body. We provide a wide range of qualifications
Answer Book. If you change your mind, put a line through the box and then mark
your new answer with a cross . including academic, vocational, occupational and specific
programmes for employers. For further information visit our
1 An atom has electrons in two s orbitals and three p orbitals.
qualifications websites at or .
What is the maximum number of electrons that this atom can have? Alternatively, you can get in touch with us using the details on our
contact us page at
A 2
B 5
C 7
D 10
(Total for Question 1 = 1 mark)
Pearson: helping people progress, everywhere
2 What is meant by the term carbon neutrality when referring to fuels?
Pearson aspires to be the world’s leading learning company. Our aim is to help everyone
A all combustion products of the fuel are neutral 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
B on combustion the fuel releases zero carbon and carbon dioxide
years, and by working across 70 countries, in 100 languages, we have built an
C equal amounts of carbon are emitted to and absorbed from the atmosphere 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
D equal amounts of carbon dioxide are emitted to and absorbed from students at:
the atmosphere
(Total for Question 2 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
Summer 2026
Question Paper Log Number P81804A
Publication Code WCH11_01A_2606_MS
All the material in this publication is
Pearson Education Ltd
2 P81804A
,3 Alkanes are used as fuels. General Marking Guidance
A simplified diagram of a fractionating column is shown.
• All candidates must receive the same treatment. Examiners must mark the first
X
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
Y used appropriately.
W
• 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
Z scheme. Examiners should also be prepared to award zero marks if the
Which fraction contains molecules with the shortest average chain length? 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
A W which marks will be awarded and exemplification may be limited.
B X • When examiners are in doubt regarding the application of the mark scheme to a
C Y candidate’s response, the team leader must be consulted.
• Crossed out work should be marked UNLESS the candidate has replaced it with
D Z
an alternative response.
(Total for Question 3 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
P81804A 3
Turn over
, 4 (a) Which condition is essential for cracking? Using the Mark Scheme
(1)
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
A oxygen
allowing candidates to be rewarded for answers showing correct application of
B phosphoric(V) acid catalyst 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.
C ultraviolet radiation
D zeolite catalyst The mark scheme gives examiners:
• an idea of the types of response expected
4 (b) Why is cracking used for the processing of some crude oil fractions? • how individual marks are to be awarded
(1) • the total mark for each question
• examples of responses that should NOT receive credit.
A to produce fuels that burn more efficiently
/ means that the responses are alternatives and either answer should receive full
B to remove impurities from the fractions
credit.
C to convert long chain alkanes into shorter, more useful alkenes ( ) 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.
D to increase the chain length of the alkanes
4 Which reaction does not occur in the reforming of heptane? Phrases/words in bold indicate that the meaning of the phrase or the actual word is
(1) 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.
A
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
B + H2 are put together in a meaningless manner. Answers must be in the correct context.
Quality of Written Communication
C + H2
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
D + 3H2 • 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
4 (d) Which reaction is not involved in the formation of acid rain? appropriate.
(1)
Full marks will be awarded if the candidate has demonstrated the above abilities.
A N2 + O2 → 2NO Questions where QWC is likely to be particularly important are indicated (QWC) in the
mark scheme, but this does not preclude others.
B 2NO + O2 → 2NO2
C C8H18 + 12½O2 → 9H2O + 8CO2
D 2SO2 + O2 → 2SO3
4 P81804A
Wednesday 6 May 2026
WCH11/01A
Paper
Afternoon (Time: 1 hour 30 minutes)
reference
Chemistry
International Advanced Subsidiary/Advanced Level
UNIT 1: Structure, Bonding and Introduction to Mark Scheme (Results)
Organic Chemistry
Question Paper
You must have:
Scientific calculator, ruler and Answer Book (sent separately)
Summer 2026
Pearson Edexcel International Advanced
Subsidiary Level In Chemistry
WCH11/01A
Turn over
P81804APearson Education Ltd.
P:1/1/1/1/1/1
*P81804A*
, SECTION A Edexcel and BTEC Qualifications
Answer ALL the questions in this section in the Answer Book.
You should aim to spend no more than 20 minutes on this section.
Edexcel and BTEC qualifications are awarded by Pearson, the UK’s
For each question, select one answer from A to D and put a cross in the box in the
largest awarding body. We provide a wide range of qualifications
Answer Book. If you change your mind, put a line through the box and then mark
your new answer with a cross . including academic, vocational, occupational and specific
programmes for employers. For further information visit our
1 An atom has electrons in two s orbitals and three p orbitals.
qualifications websites at or .
What is the maximum number of electrons that this atom can have? Alternatively, you can get in touch with us using the details on our
contact us page at
A 2
B 5
C 7
D 10
(Total for Question 1 = 1 mark)
Pearson: helping people progress, everywhere
2 What is meant by the term carbon neutrality when referring to fuels?
Pearson aspires to be the world’s leading learning company. Our aim is to help everyone
A all combustion products of the fuel are neutral 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
B on combustion the fuel releases zero carbon and carbon dioxide
years, and by working across 70 countries, in 100 languages, we have built an
C equal amounts of carbon are emitted to and absorbed from the atmosphere 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
D equal amounts of carbon dioxide are emitted to and absorbed from students at:
the atmosphere
(Total for Question 2 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
Summer 2026
Question Paper Log Number P81804A
Publication Code WCH11_01A_2606_MS
All the material in this publication is
Pearson Education Ltd
2 P81804A
,3 Alkanes are used as fuels. General Marking Guidance
A simplified diagram of a fractionating column is shown.
• All candidates must receive the same treatment. Examiners must mark the first
X
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
Y used appropriately.
W
• 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
Z scheme. Examiners should also be prepared to award zero marks if the
Which fraction contains molecules with the shortest average chain length? 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
A W which marks will be awarded and exemplification may be limited.
B X • When examiners are in doubt regarding the application of the mark scheme to a
C Y candidate’s response, the team leader must be consulted.
• Crossed out work should be marked UNLESS the candidate has replaced it with
D Z
an alternative response.
(Total for Question 3 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
P81804A 3
Turn over
, 4 (a) Which condition is essential for cracking? Using the Mark Scheme
(1)
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
A oxygen
allowing candidates to be rewarded for answers showing correct application of
B phosphoric(V) acid catalyst 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.
C ultraviolet radiation
D zeolite catalyst The mark scheme gives examiners:
• an idea of the types of response expected
4 (b) Why is cracking used for the processing of some crude oil fractions? • how individual marks are to be awarded
(1) • the total mark for each question
• examples of responses that should NOT receive credit.
A to produce fuels that burn more efficiently
/ means that the responses are alternatives and either answer should receive full
B to remove impurities from the fractions
credit.
C to convert long chain alkanes into shorter, more useful alkenes ( ) 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.
D to increase the chain length of the alkanes
4 Which reaction does not occur in the reforming of heptane? Phrases/words in bold indicate that the meaning of the phrase or the actual word is
(1) 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.
A
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
B + H2 are put together in a meaningless manner. Answers must be in the correct context.
Quality of Written Communication
C + H2
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
D + 3H2 • 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
4 (d) Which reaction is not involved in the formation of acid rain? appropriate.
(1)
Full marks will be awarded if the candidate has demonstrated the above abilities.
A N2 + O2 → 2NO Questions where QWC is likely to be particularly important are indicated (QWC) in the
mark scheme, but this does not preclude others.
B 2NO + O2 → 2NO2
C C8H18 + 12½O2 → 9H2O + 8CO2
D 2SO2 + O2 → 2SO3
4 P81804A
