Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
CHEMISTRY
Paper 2 Organic and Physical Chemistry
Tuesday 20 May 2025 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have:
• the Periodic Table/Data Sheet, provided as an insert (enclosed) For Examiner’s Use
• a ruler with millimetre measurements Question Mark
• a scientific calculator, which you are expected to use where appropriate.
1
Instructions 2
• Use black ink or black ball-point pen. 3
• Fill in the boxes at the top of this page. 4
• Answer all questions.
5
• You must answer the questions in the spaces provided. Do not write outside
the box around each page or on blank pages. 6
• If you need extra space for your answer(s), use the lined pages at the end of 7
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 65 minutes on Section A and 25 minutes on Section B.
*Jun257404201*
IB/M/Jun25/G4002/V7 7404/2
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 This question is about halogenoalkanes.
0 1 . 1 Halogenoalkanes undergo substitution reactions with nucleophiles such as
CN–, NH3 and OH–
Explain why halogenoalkanes react with nucleophiles.
[2 marks]
0 1 . 2 2-Bromobutane reacts with ammonia to form CH3CH(NH2)CH2CH3
Complete the mechanism for this reaction.
[3 marks]
2-Bromobutane reacts with KOH to give a mixture of products.
0 1 . 3 Identify the solvent that should be used to ensure that butan-2-ol is the
main organic product when 2-brombutane reacts with KOH
[1 mark]
*02*
IB/M/Jun25/7404/2
, 3
Do not write
outside the
0 1 . 4 Under different conditions, 2-bromobutane reacts with KOH to form but-1-ene and box
two other alkenes.
Name and complete the mechanism to form but-1-ene from 2-bromobutane.
Identify the other two alkenes formed.
[5 marks]
Name of mechanism
Mechanism
Other alkene 1
Other alkene 2
0 1 . 5 The carbocation (CH3)3C+ is formed as an intermediate in the reaction of
2-bromo-2-methylpropane with KCN
Suggest the value of the bond angle around the central C atom in the
(CH3)3C+ carbocation.
[1 mark]
Question 1 continues on the next page
Turn over ►
*03*
IB/M/Jun25/7404/2
, 4
Do not write
outside the
0 1 . 6 A co-ordinate bond is formed when the (CH3)3C+ carbocation reacts with CN– to box
form a nitrile.
Explain how this co-ordinate bond is formed during this reaction.
[2 marks]
14
*04*
IB/M/Jun25/7404/2
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
CHEMISTRY
Paper 2 Organic and Physical Chemistry
Tuesday 20 May 2025 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have:
• the Periodic Table/Data Sheet, provided as an insert (enclosed) For Examiner’s Use
• a ruler with millimetre measurements Question Mark
• a scientific calculator, which you are expected to use where appropriate.
1
Instructions 2
• Use black ink or black ball-point pen. 3
• Fill in the boxes at the top of this page. 4
• Answer all questions.
5
• You must answer the questions in the spaces provided. Do not write outside
the box around each page or on blank pages. 6
• If you need extra space for your answer(s), use the lined pages at the end of 7
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 65 minutes on Section A and 25 minutes on Section B.
*Jun257404201*
IB/M/Jun25/G4002/V7 7404/2
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 This question is about halogenoalkanes.
0 1 . 1 Halogenoalkanes undergo substitution reactions with nucleophiles such as
CN–, NH3 and OH–
Explain why halogenoalkanes react with nucleophiles.
[2 marks]
0 1 . 2 2-Bromobutane reacts with ammonia to form CH3CH(NH2)CH2CH3
Complete the mechanism for this reaction.
[3 marks]
2-Bromobutane reacts with KOH to give a mixture of products.
0 1 . 3 Identify the solvent that should be used to ensure that butan-2-ol is the
main organic product when 2-brombutane reacts with KOH
[1 mark]
*02*
IB/M/Jun25/7404/2
, 3
Do not write
outside the
0 1 . 4 Under different conditions, 2-bromobutane reacts with KOH to form but-1-ene and box
two other alkenes.
Name and complete the mechanism to form but-1-ene from 2-bromobutane.
Identify the other two alkenes formed.
[5 marks]
Name of mechanism
Mechanism
Other alkene 1
Other alkene 2
0 1 . 5 The carbocation (CH3)3C+ is formed as an intermediate in the reaction of
2-bromo-2-methylpropane with KCN
Suggest the value of the bond angle around the central C atom in the
(CH3)3C+ carbocation.
[1 mark]
Question 1 continues on the next page
Turn over ►
*03*
IB/M/Jun25/7404/2
, 4
Do not write
outside the
0 1 . 6 A co-ordinate bond is formed when the (CH3)3C+ carbocation reacts with CN– to box
form a nitrile.
Explain how this co-ordinate bond is formed during this reaction.
[2 marks]
14
*04*
IB/M/Jun25/7404/2
