Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
A-level
CHEMISTRY
Paper 1 Inorganic and Physical Chemistry
Tuesday 4 June 2025 Afternoon Time allowed: 2 hours
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
• All working must be shown. 8
• Do all rough work in this book. Cross through any work you do not
want to be marked. 9
TOTAL
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 105.
*JUN197405101*
IB/G/Jun19/E16 7405/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 Figure 1 shows an incomplete Born–Haber cycle for the formation of caesium iodide.
The diagram is not to scale.
Figure 1
Table 1 gives values of some standard enthalpy changes.
Table 1
Name of enthalpy change ∆Ho / kJ mol–1
Enthalpy of atomisation of caesium +79
First ionisation energy of caesium +376
Electron affinity of iodine –314
Enthalpy of lattice formation of caesium iodide –585
Enthalpy of formation of caesium iodide –337
0 1 . 1 Complete Figure 1 by writing the formulas, including state symbols, of the appropriate
species on each of the two blank lines.
[2 marks]
0 1 . 2 Use Figure 1 and the data in Table 1 to calculate the standard enthalpy of
atomisation of iodine.
[2 marks]
Standard enthalpy of atomisation of iodine kJ mol-1
*02*
IB/G/Jun19/7405/1
, 3
Do not write
outside the
box
0 1 . 3 The enthalpy of lattice formation for caesium iodide in Table 1 is a value obtained
by experiment.
The value obtained by calculation using the perfect ionic model is –582 kJ mol–1
Deduce what these values indicate about the bonding in caesium iodide.
[1 mark]
0 1 . 4 Use data from Table 2 to show that this reaction is not feasible at 298 K
1
CsI(s) → Cs(s) + I2(s) ∆Ho = +337 kJ mol–1
2
Table 2
CsI(s) Cs(s) I2(s)
So / J K–1 mol–1 130 82.8 117
[4 marks]
9
Turn over ►
*03*
IB/G/Jun19/7405/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
A-level
CHEMISTRY
Paper 1 Inorganic and Physical Chemistry
Tuesday 4 June 2025 Afternoon Time allowed: 2 hours
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
• All working must be shown. 8
• Do all rough work in this book. Cross through any work you do not
want to be marked. 9
TOTAL
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 105.
*JUN197405101*
IB/G/Jun19/E16 7405/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 Figure 1 shows an incomplete Born–Haber cycle for the formation of caesium iodide.
The diagram is not to scale.
Figure 1
Table 1 gives values of some standard enthalpy changes.
Table 1
Name of enthalpy change ∆Ho / kJ mol–1
Enthalpy of atomisation of caesium +79
First ionisation energy of caesium +376
Electron affinity of iodine –314
Enthalpy of lattice formation of caesium iodide –585
Enthalpy of formation of caesium iodide –337
0 1 . 1 Complete Figure 1 by writing the formulas, including state symbols, of the appropriate
species on each of the two blank lines.
[2 marks]
0 1 . 2 Use Figure 1 and the data in Table 1 to calculate the standard enthalpy of
atomisation of iodine.
[2 marks]
Standard enthalpy of atomisation of iodine kJ mol-1
*02*
IB/G/Jun19/7405/1
, 3
Do not write
outside the
box
0 1 . 3 The enthalpy of lattice formation for caesium iodide in Table 1 is a value obtained
by experiment.
The value obtained by calculation using the perfect ionic model is –582 kJ mol–1
Deduce what these values indicate about the bonding in caesium iodide.
[1 mark]
0 1 . 4 Use data from Table 2 to show that this reaction is not feasible at 298 K
1
CsI(s) → Cs(s) + I2(s) ∆Ho = +337 kJ mol–1
2
Table 2
CsI(s) Cs(s) I2(s)
So / J K–1 mol–1 130 82.8 117
[4 marks]
9
Turn over ►
*03*
IB/G/Jun19/7405/1
