Pearson Edexcel Level GCE Advance

Mark Scheme (Results) Summer 2025 Pearson Edexcel Level GCE Advance Subsidiary In Chemistry (8CH0) Paper 02: Core Organic and Physical Chemistry Edexcel and BTEC Qualifications Edexcel and BTEC qualifications come from Pearson, the world’s leading learning company. We provide a wide range of qualifications including academic, vocational, occupational and specific programmes for employers. For further information visit our qualifications websites at or for our BTEC qualifications. Alternatively, you can get in touch with us using the details on our contact us page at 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: Summer 2025 Question Paper Log Number: P77831A Publications Code: 8CH0_02_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. • Mark schemes will indicate within the table where, and which strands of QWC, are being assessed. The strands are as follows: i) ensure that text is legible and that spelling, punctuation and grammar are accurate so that meaning is clear ii) select and use a form and style of writing appropriate to purpose and to complex subject matter iii) organise information clearly and coherently, using specialist vocabulary when appropriate. 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. Question Number Answer Mark 1(a) The only correct answer is D (C10H16) A is incorrect because this answer miscounts both the number of carbon atoms in the skeletal formula and the number of hydrogen atoms in the skeletal formula, and it is the empirical formula B is incorrect because C5H8 is the empirical formula of myrcene C is incorrect because this answer miscounts the number of hydrogen atoms in the skeletal formula (1) Question Number Answer Mark 1(b) The only correct answer is B (3) A is incorrect because there are three C=C double bonds where bromine could add C is incorrect because there are three C=C double bonds where bromine could add D is incorrect because this is the number of bromine atoms added and not the number of bromine molecules (1) Question Number Answer Mark 1(c) The only correct answer is B (2-methylbuta-1,3-diene) A is incorrect because there are two double bonds and so there should be a di before the ene C is incorrect because the IUPAC system requires this to be named as substituted butadiene D is incorrect because this name indicates a total of 6 carbon atoms and a chain of 5 carbon atoms (1) Question Number Answer Mark 1(d) The only correct answer is C (acidified potassium manganate(VII)) A is incorrect because this would produce an alkane B is incorrect because there would be no reaction D is incorrect because this would produce an alcohol (1)