Please check the examination details below before entering your candidate information
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Monday 8 January 2024
Morning (Time: 1 hour 45 minutes) Paper
reference WCH14/01
Chemistry
International Advanced Level
UNIT 4: Rates, Equilibria and Further Organic
Chemistry
You must have: Total Marks
Scientific calculator, Data Booklet, ruler
Instructions
•• Use black ink or ball‑point pen.
If pencil is used for diagrams/sketches/graphs it must be dark (HB or B).
• Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 90.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• Instructure
the question marked with an asterisk (*), marks will be awarded for your ability to
your answer logically, showing how the points that you make are related or
follow on from each other where appropriate.
• A Periodic Table is printed on the back cover of this paper.
Advice
•• Read each question carefully before you start to answer it.
Show all your working in calculations and include units where appropriate.
•• Try to answer every question.
Check your answers if you have time at the end.
Turn over
P73456A
©2024 Pearson Education Ltd.
S:1/1/1/
*P73456A0128*
, SECTION A
Answer ALL the questions in this section.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
You should aim to spend no more than 20 minutes on this section.
For each question, select one answer from A to D and put a cross in the box . If you change
your mind, put a line through the box and then mark your new answer with a cross .
1 The equation for a reaction is shown.
A(g) + 2B(g) 3C(s) + 4D(g)
(a) Some collisions between reactant molecules do not lead to the formation
of products.
What is the best explanation for this?
(1)
A the reactant concentrations are too low
B the collisions do not have sufficient energy
C the reaction is at equilibrium
D the molecules do not collide in the correct ratio
(b) What are the units of the equilibrium constant, Kp , for this reaction?
(1)
A atm
B atm–1
C atm4
D atm–4
(Total for Question 1 = 2 marks)
2 Nitrogen(V) oxide, N2O5 , decomposes in a first order reaction.
At 45 °C, the half‑life for this reaction is 1400 s.
In an experiment, the initial concentration of nitrogen(V) oxide is 1.0 mol dm–3.
What is the concentration, in mol dm–3, of nitrogen(V) oxide after 4200 s?
A 0.875
B 0.500
C 0.250
D 0.125
(Total for Question 2 = 1 mark)
2
*P73456A0228*
, 3 Ammonia is produced by the reaction of nitrogen with hydrogen in the presence of
an iron catalyst.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
N2(g) + 3H2(g) 2NH3(g) ΔH = –92 kJ mol–1
(a) Which of the following statements about the catalyst is not correct?
(1)
A it lowers the activation energy of the reaction
B it has no effect on the equilibrium constant for the reaction
C it alters the enthalpy change of the reaction
D it reduces the energy cost of the reaction
(b) Which conditions favour the highest percentage of ammonia in an equilibrium
mixture from identical amounts of nitrogen and hydrogen?
(1)
A a temperature of 400 K and a pressure of 200 kPa
B a temperature of 400 K and a pressure of 200 atm
C a temperature of 400 °C and a pressure of 200 kPa
D a temperature of 400 °C and a pressure of 200 atm
(Total for Question 3 = 2 marks)
4 The equations for three reactions involving hydrogen are shown.
J N2(g) + 3H2(g) → 2NH3(g)
K N2(g) + 2H2(g) → N2H4(l )
L I2(s) + H2(g) → 2HI(g)
What is the order of increasing standard entropy change of the system, ΔS system
d
, for
these reactions?
A J, K, L
B K, L, J
C K, J, L
D L, K, J
(Total for Question 4 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
3
*P73456A0328* Turn over
, 5 Methane reacts with steam to produce carbon dioxide and hydrogen.
CH4(g) + 2H2O(g) → CO2(g) + 4H2(g)
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
The standard molar entropies of the reactants and products are given in the table.
Substance S d / J K–1 mol–1
CH4(g) 186
H2O(g) 189
CO2(g) 214
H2(g) 131
The value of ΔS system
d
for this reaction, in J K–1 mol–1, is
A –174
B –30
C +30
D +174
(Total for Question 5 = 1 mark)
6 What are the signs of the entropy changes at 373 K when water vapour condenses?
H2O(g) → H2O(l )
ΔSsystem ΔSsurroundings
A positive positive
B positive negative
C negative positive
D negative negative
(Total for Question 6 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
4
*P73456A0428*
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Monday 8 January 2024
Morning (Time: 1 hour 45 minutes) Paper
reference WCH14/01
Chemistry
International Advanced Level
UNIT 4: Rates, Equilibria and Further Organic
Chemistry
You must have: Total Marks
Scientific calculator, Data Booklet, ruler
Instructions
•• Use black ink or ball‑point pen.
If pencil is used for diagrams/sketches/graphs it must be dark (HB or B).
• Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 90.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• Instructure
the question marked with an asterisk (*), marks will be awarded for your ability to
your answer logically, showing how the points that you make are related or
follow on from each other where appropriate.
• A Periodic Table is printed on the back cover of this paper.
Advice
•• Read each question carefully before you start to answer it.
Show all your working in calculations and include units where appropriate.
•• Try to answer every question.
Check your answers if you have time at the end.
Turn over
P73456A
©2024 Pearson Education Ltd.
S:1/1/1/
*P73456A0128*
, SECTION A
Answer ALL the questions in this section.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
You should aim to spend no more than 20 minutes on this section.
For each question, select one answer from A to D and put a cross in the box . If you change
your mind, put a line through the box and then mark your new answer with a cross .
1 The equation for a reaction is shown.
A(g) + 2B(g) 3C(s) + 4D(g)
(a) Some collisions between reactant molecules do not lead to the formation
of products.
What is the best explanation for this?
(1)
A the reactant concentrations are too low
B the collisions do not have sufficient energy
C the reaction is at equilibrium
D the molecules do not collide in the correct ratio
(b) What are the units of the equilibrium constant, Kp , for this reaction?
(1)
A atm
B atm–1
C atm4
D atm–4
(Total for Question 1 = 2 marks)
2 Nitrogen(V) oxide, N2O5 , decomposes in a first order reaction.
At 45 °C, the half‑life for this reaction is 1400 s.
In an experiment, the initial concentration of nitrogen(V) oxide is 1.0 mol dm–3.
What is the concentration, in mol dm–3, of nitrogen(V) oxide after 4200 s?
A 0.875
B 0.500
C 0.250
D 0.125
(Total for Question 2 = 1 mark)
2
*P73456A0228*
, 3 Ammonia is produced by the reaction of nitrogen with hydrogen in the presence of
an iron catalyst.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
N2(g) + 3H2(g) 2NH3(g) ΔH = –92 kJ mol–1
(a) Which of the following statements about the catalyst is not correct?
(1)
A it lowers the activation energy of the reaction
B it has no effect on the equilibrium constant for the reaction
C it alters the enthalpy change of the reaction
D it reduces the energy cost of the reaction
(b) Which conditions favour the highest percentage of ammonia in an equilibrium
mixture from identical amounts of nitrogen and hydrogen?
(1)
A a temperature of 400 K and a pressure of 200 kPa
B a temperature of 400 K and a pressure of 200 atm
C a temperature of 400 °C and a pressure of 200 kPa
D a temperature of 400 °C and a pressure of 200 atm
(Total for Question 3 = 2 marks)
4 The equations for three reactions involving hydrogen are shown.
J N2(g) + 3H2(g) → 2NH3(g)
K N2(g) + 2H2(g) → N2H4(l )
L I2(s) + H2(g) → 2HI(g)
What is the order of increasing standard entropy change of the system, ΔS system
d
, for
these reactions?
A J, K, L
B K, L, J
C K, J, L
D L, K, J
(Total for Question 4 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
3
*P73456A0328* Turn over
, 5 Methane reacts with steam to produce carbon dioxide and hydrogen.
CH4(g) + 2H2O(g) → CO2(g) + 4H2(g)
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
The standard molar entropies of the reactants and products are given in the table.
Substance S d / J K–1 mol–1
CH4(g) 186
H2O(g) 189
CO2(g) 214
H2(g) 131
The value of ΔS system
d
for this reaction, in J K–1 mol–1, is
A –174
B –30
C +30
D +174
(Total for Question 5 = 1 mark)
6 What are the signs of the entropy changes at 373 K when water vapour condenses?
H2O(g) → H2O(l )
ΔSsystem ΔSsurroundings
A positive positive
B positive negative
C negative positive
D negative negative
(Total for Question 6 = 1 mark)
Use this space for any rough working. Anything you write in this space will gain no credit.
4
*P73456A0428*
