Organic & Physical Chemistry | Past Paper +
Mark Scheme (June 2025, Verified &
Merged Edition
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AS
CHEMISTRY
Paper 2 Organic and Physical Chemistry
Tuesday 23 May 2023 Morning Time allowed: 1 hour 30 minutes
Materials For Examiner’s Use
For this paper you must have:
• the Periodic Table/Data Sheet, provided as an insert (enclosed) Question Mark
• a ruler with millimetre measurements
1
• a scientific calculator, which you are expected to use where appropriate.
2
Instructions 3
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page.
5
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write outside 6
the box around each page or on blank pages. 7
• If you need extra space for your answer(s), use the lined pages at the end of 8
this book. Write the question number against your answer(s).
Section B
• All working must be shown.
• Do all rough work in this book. Cross through any work you do not TOTAL
want to be marked.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 80.
Advice
You are advised to spend about 65 minutes on Section A and 25 minutes on Section B.
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1This question is about the analysis of organic compounds.
For each pair of compounds in Questions 01.1 and 01.2, give a reagent (or
combination of reagents) that could be added separately to each compound in a
single reaction to distinguish between them.
State what is observed in each case.
0 1 . 1CH3CH2CH2CHO and CH3CH2CH(OH)CH3
[3 marks]
Reagent(s)
Observation with CH3CH2CH2CHO
Observation with CH3CH2CH(OH)CH3
0 1.2
Cyclohexane and cyclohexene
[3 marks]
Reagent(s)
Observation with cyclohexane
Observation with cyclohexene
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outside the
0 1 . 3 Table 1 gives the precise relative molecular masses (Mr) of some organic compounds box
measured using high resolution mass spectrometry.
Table 1
Molecular formula C5H12 C5H10 C6H6
Mr 72.1416 70.1260 to be calculated
Use these data to find the relative atomic masses (Ar) of hydrogen and carbon.
Give your answers to 4 decimal places.
Use these calculated Ar values to find the relative molecular mass (Mr) of C6H6
Give your answer to 4 decimal places.
[3 marks]
Ar of hydrogen
Ar of carbon
Mr of C6H6 9
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0 2 This question is about fuels. box
0 2 . 1 Crude oil is separated into fractions by fractional distillation.
State the meaning of the term ‘fraction’ in this context.
[1 mark]
0 2 . 2 Petrol for cars contains branched and cyclic alkanes produced by catalytic cracking.
Identify the catalyst used in this process.
[1 mark]
0 2 . 3 3-Ethyl-4-methylhexane is a branched alkane in petrol.
Draw the skeletal formula of this alkane.
[1 mark]
0 2 . 4 Give the equation for the complete combustion of 3-ethyl-4-methylhexane.
Use the molecular formula for 3-ethyl-4-methylhexane in your equation.
[2 marks]
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outside the
0 2 . 5 Carbon dioxide is a product from the combustion of petrol in cars. Carbon dioxide box
acts as a greenhouse gas when it absorbs infrared radiation.
Give one reason why carbon dioxide absorbs infrared radiation.
[1 mark]
0 2 . 6 Nitrogen monoxide (NO) is formed when petrol is burned in cars.
State one environmental problem that NO causes.
State what is used to remove NO from the exhaust gases formed in
petrol-fuelled cars.
[2 marks]
Environmental problem
Removal of NO
0 2 . 7 Petrol sold in the UK contains 10% bioethanol. Bioethanol is ethanol made from crops by
fermentation and is considered to be carbon-neutral.
State what is meant by the term ‘carbon-neutral’.
[1 mark]
9
Turn over for the next question
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