Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
INTERNATIONAL AS
CHEMISTRY (9620)
Unit 1: Inorganic 1 and Physical 1
Monday 6 January 2025 07:00 GMT Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• the Periodic Table/Data Sheet, provided as an insert 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.
• Answer all questions. 5
• You must answer the questions in the spaces provided. Do not write 6
outside 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
this book. Write the question number against your answer(s). TOTAL
• 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 70.
IB/G/Jan25/G4003/V5 CH01
box
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 This question is about atomic structure.
0 1 . 1 Table 1 shows the relative charge of a proton and the relative mass of an electron.
Complete Table 1.
[2 marks]
Table 1
Proton Electron Neutron
Relative charge +1
Relative mass 1
0 1 . 2 An atom has two more protons and two more neutrons than an atom of 30Si
Give the symbol of the atom, including mass number.
[1 mark]
0 1 . 3 Complete the electron configuration for a S atom and for a V2+ ion.
[2 marks]
S [Ne]
V2+ [Ar]
0 1 . 4 In terms of sub-atomic particles, explain how isotopes of an element differ.
State why these isotopes have the same chemical reactions.
[2 marks]
How isotopes differ
Why same chemical reactions
7
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IB/G/Jan25/CH01
, 3
Do not write
outside the
0 2 This question is about carbon monoxide. box
0 2 . 1 State the type of crystal structure of solid carbon monoxide.
[1 mark]
0 2 . 2 Carbon monoxide is formed in a reaction from ethene (C2H4).
C2 H4(g) + 2 O2(g) → 2 CO(g) + 2 H2O(g) ΔH ϴ = −758 kJ mol–1
Table 2 shows some standard enthalpy of formation data.
Table 2
C2H4(g) H2O(g)
−1
ΔfH ϴ / kJ mol +52 −242
State Hess’s Law.
Use Hess’s Law and the data in Table 2 to calculate the standard enthalpy of formation,
in kJ mol–1, of carbon monoxide.
[4 marks]
Hess’s Law
Calculation
Standard enthalpy of formation _______________________________ kJ mol–1
IB/G/Jan25/CH01
, 4
Do not write
outside the
0 2 . 3 Carbon monoxide burns in oxygen to form carbon dioxide. box
1
CO(g) + O (g) → CO (g) ΔH ϴ = −283 kJ mol–1
2 2 2
The bond enthalpy for O═O is 496 kJ mol–1
The mean bond enthalpy for C═O in carbon dioxide is 804 kJ mol–1
Calculate the bond enthalpy, in kJ mol–1, for the bond between the carbon atom and
the oxygen atom in carbon monoxide.
[2 marks]
Bond enthalpy ________________________ kJ mol–1
0 2 . 4 Suggest why the value for O═O is not given as a mean bond enthalpy.
[1 mark]
0 2 . 5 The boiling point of carbon monoxide is 82 K
Explain why the boiling point of carbon monoxide is low.
[2 marks]
10
Turn over ►
IB/G/Jan25/CH01
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
INTERNATIONAL AS
CHEMISTRY (9620)
Unit 1: Inorganic 1 and Physical 1
Monday 6 January 2025 07:00 GMT Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• the Periodic Table/Data Sheet, provided as an insert 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.
• Answer all questions. 5
• You must answer the questions in the spaces provided. Do not write 6
outside 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
this book. Write the question number against your answer(s). TOTAL
• 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 70.
IB/G/Jan25/G4003/V5 CH01
box
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 This question is about atomic structure.
0 1 . 1 Table 1 shows the relative charge of a proton and the relative mass of an electron.
Complete Table 1.
[2 marks]
Table 1
Proton Electron Neutron
Relative charge +1
Relative mass 1
0 1 . 2 An atom has two more protons and two more neutrons than an atom of 30Si
Give the symbol of the atom, including mass number.
[1 mark]
0 1 . 3 Complete the electron configuration for a S atom and for a V2+ ion.
[2 marks]
S [Ne]
V2+ [Ar]
0 1 . 4 In terms of sub-atomic particles, explain how isotopes of an element differ.
State why these isotopes have the same chemical reactions.
[2 marks]
How isotopes differ
Why same chemical reactions
7
Turn over ►
IB/G/Jan25/CH01
, 3
Do not write
outside the
0 2 This question is about carbon monoxide. box
0 2 . 1 State the type of crystal structure of solid carbon monoxide.
[1 mark]
0 2 . 2 Carbon monoxide is formed in a reaction from ethene (C2H4).
C2 H4(g) + 2 O2(g) → 2 CO(g) + 2 H2O(g) ΔH ϴ = −758 kJ mol–1
Table 2 shows some standard enthalpy of formation data.
Table 2
C2H4(g) H2O(g)
−1
ΔfH ϴ / kJ mol +52 −242
State Hess’s Law.
Use Hess’s Law and the data in Table 2 to calculate the standard enthalpy of formation,
in kJ mol–1, of carbon monoxide.
[4 marks]
Hess’s Law
Calculation
Standard enthalpy of formation _______________________________ kJ mol–1
IB/G/Jan25/CH01
, 4
Do not write
outside the
0 2 . 3 Carbon monoxide burns in oxygen to form carbon dioxide. box
1
CO(g) + O (g) → CO (g) ΔH ϴ = −283 kJ mol–1
2 2 2
The bond enthalpy for O═O is 496 kJ mol–1
The mean bond enthalpy for C═O in carbon dioxide is 804 kJ mol–1
Calculate the bond enthalpy, in kJ mol–1, for the bond between the carbon atom and
the oxygen atom in carbon monoxide.
[2 marks]
Bond enthalpy ________________________ kJ mol–1
0 2 . 4 Suggest why the value for O═O is not given as a mean bond enthalpy.
[1 mark]
0 2 . 5 The boiling point of carbon monoxide is 82 K
Explain why the boiling point of carbon monoxide is low.
[2 marks]
10
Turn over ►
IB/G/Jan25/CH01
