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 19 May 2026 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
3
Instructions
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page. 5
• Answer all questions.
6
• You must answer the questions in the spaces provided. Do not write outside
the box around each page or on blank pages. Section B
• If you need extra space for your answer(s), use the lined pages at the end of TOTAL
this book. Write the question number against your answer(s).
• All working must be shown.
• Do all rough work in this book. Cross through any work you do not
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.
*Jun267404201*
7404/2
for more:
IB/M/Jun26/G4003/V6
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 This question is about the decomposition of methane gas.
Figure 1 shows the Maxwell–Boltzmann distribution of molecular energies for
10 mol of methane gas in a container of fixed volume.
Figure 1
0 1 . 1 Label the y-axis on Figure 1.
[1 mark]
0 1 . 2 The pressure of the methane in the container is increased by adding a further
10 mol of methane.
The temperature remains constant.
Sketch a curve on Figure 1 to show the new distribution of molecular energies.
[2 marks]
*02* for more:
IB/M/Jun26/7404/2
, 3
Do not write
outside the
0 1 . 3 Methane decomposes into carbon and hydrogen at 1200 °C box
CH4(g) → C(s) + 2 H2(g)
Explain why the rate of decomposition increases at higher pressure.
[2 marks]
0 1 . 4 The rate of decomposition can also be increased by adding a catalyst.
The activation energy for the uncatalysed reaction is shown as Ea on Figure 1.
Label Figure 1 with an X to show the activation energy for the catalysed reaction.
[1 mark]
0 1 . 5 Table 1 shows some enthalpy change data.
Table 1
ΔH / kJ mol–1
CH4(g) → C(s) + 2 H2(g) +76
Bond enthalpy for H–H +436
C(s) → C(g) +715
Use the data in Table 1 to calculate the mean C–H bond enthalpy in methane.
[2 marks]
Mean C–H bond enthalpy kJ mol–1
Turn over ►
*03* for more:
IB/M/Jun26/7404/2
, 4
Do not write
outside the
0 1 . 6 State why the mean bond enthalpy for the C–H bond calculated in Question 01.5 is box
different from the mean value for the C–H bond found in data books.
[1 mark]
0 1 . 7 Hydrogen obtained from the decomposition of methane can be used as a fuel.
Table 2 shows data about the use of methane and hydrogen as fuels.
Table 2
H2(g) CH4(g)
Enthalpy of combustion / kJ mol–1 –286 –890
Energy density / kJ g–1 143 To be calculated
Calculate the energy density of methane.
[1 mark]
Energy density of methane kJ g–1
*04* for more:
IB/M/Jun26/7404/2
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 19 May 2026 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
3
Instructions
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page. 5
• Answer all questions.
6
• You must answer the questions in the spaces provided. Do not write outside
the box around each page or on blank pages. Section B
• If you need extra space for your answer(s), use the lined pages at the end of TOTAL
this book. Write the question number against your answer(s).
• All working must be shown.
• Do all rough work in this book. Cross through any work you do not
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.
*Jun267404201*
7404/2
for more:
IB/M/Jun26/G4003/V6
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 This question is about the decomposition of methane gas.
Figure 1 shows the Maxwell–Boltzmann distribution of molecular energies for
10 mol of methane gas in a container of fixed volume.
Figure 1
0 1 . 1 Label the y-axis on Figure 1.
[1 mark]
0 1 . 2 The pressure of the methane in the container is increased by adding a further
10 mol of methane.
The temperature remains constant.
Sketch a curve on Figure 1 to show the new distribution of molecular energies.
[2 marks]
*02* for more:
IB/M/Jun26/7404/2
, 3
Do not write
outside the
0 1 . 3 Methane decomposes into carbon and hydrogen at 1200 °C box
CH4(g) → C(s) + 2 H2(g)
Explain why the rate of decomposition increases at higher pressure.
[2 marks]
0 1 . 4 The rate of decomposition can also be increased by adding a catalyst.
The activation energy for the uncatalysed reaction is shown as Ea on Figure 1.
Label Figure 1 with an X to show the activation energy for the catalysed reaction.
[1 mark]
0 1 . 5 Table 1 shows some enthalpy change data.
Table 1
ΔH / kJ mol–1
CH4(g) → C(s) + 2 H2(g) +76
Bond enthalpy for H–H +436
C(s) → C(g) +715
Use the data in Table 1 to calculate the mean C–H bond enthalpy in methane.
[2 marks]
Mean C–H bond enthalpy kJ mol–1
Turn over ►
*03* for more:
IB/M/Jun26/7404/2
, 4
Do not write
outside the
0 1 . 6 State why the mean bond enthalpy for the C–H bond calculated in Question 01.5 is box
different from the mean value for the C–H bond found in data books.
[1 mark]
0 1 . 7 Hydrogen obtained from the decomposition of methane can be used as a fuel.
Table 2 shows data about the use of methane and hydrogen as fuels.
Table 2
H2(g) CH4(g)
Enthalpy of combustion / kJ mol–1 –286 –890
Energy density / kJ g–1 143 To be calculated
Calculate the energy density of methane.
[1 mark]
Energy density of methane kJ g–1
*04* for more:
IB/M/Jun26/7404/2
