AQA A-LEVEL CHEMISTRY PAPER 3 QP JUNE 2020
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
CHEMISTRY
Paper 3
Wednesday 17 June 2020 Morning Time allowed: 2 hours
Materials
For this paper you must have: For Examiner’s Use
• the Periodic Table/Data Booklet, provided as an insert (enclosed)
Question Mark
• a ruler with millimetre measurements
• a scientific calculator, which you are expected to use where appropriate. 1
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 outside 6
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
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 90.
Advice
• You are advised to spend 70 minutes on Section A and 50 minutes on Section B.
*JUN207405301*
IB/M/Jun20/E9 7405/3
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 This question is about emissions of oxides of nitrogen from petrol and diesel engines.
0 1 . 1 Explain how oxides of nitrogen are formed in engines.
[2 marks]
0 1 . 2 State why it is desirable to decrease emissions of oxides of nitrogen from vehicles.
[1 mark]
0 1 . 3 Modern diesel vehicles use diesel exhaust fluids, such as AdBlue, to decrease
emissions of oxides of nitrogen.
AdBlue reacts with water in the hot exhaust gases to form ammonia.
In the presence of a catalyst the ammonia reacts with oxides of nitrogen to form
nitrogen and water.
Give the oxidation state of nitrogen in each of NO2, NH3 and N2
Complete the equation for the reaction between NO2 and NH3
[2 marks]
Oxidation state of nitrogen in
NO2 NH3 N2
Equation
NO2 + NH3 → N2 + H2O
*02*
IB/M/Jun20/7405/3
, 3
Do not write
outside the
0 1 . 4 Petrol vehicles have a catalytic converter which decreases emissions of oxides of box
nitrogen.
Platinum in the catalytic converter acts as a heterogeneous catalyst.
State the meaning of the term heterogeneous catalyst.
[2 marks]
0 1 . 5 Some carbon particulates are also formed in both diesel and petrol vehicles.
Explain why carbon particulates are formed.
[1 mark]
8
Turn over for the next question
Turn over ►
*03*
IB/M/Jun20/7405/3
, 4
Do not write
outside the
0 2 This question is about oxides. box
0 2 . 1 Sodium oxide forms a solution with a higher pH than magnesium oxide when equal
amounts, in moles, of each oxide are added separately to equal volumes of water.
State why both oxides form alkaline solutions.
Suggest why sodium oxide forms a solution with a higher pH than the solution formed
from magnesium oxide.
[2 marks]
0 2 . 2 Give an equation for the reaction between phosphorus(V) oxide and water.
[1 mark]
0 2 . 3 In the Contact process, sulfur(IV) oxide is converted into sulfur(VI) oxide using
vanadium(V) oxide as a catalyst.
Give two equations to show how the vanadium(V) oxide acts as a catalyst in this
process.
[2 marks]
Equation 1
Equation 2 5
*04*
IB/M/Jun20/7405/3
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
CHEMISTRY
Paper 3
Wednesday 17 June 2020 Morning Time allowed: 2 hours
Materials
For this paper you must have: For Examiner’s Use
• the Periodic Table/Data Booklet, provided as an insert (enclosed)
Question Mark
• a ruler with millimetre measurements
• a scientific calculator, which you are expected to use where appropriate. 1
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 outside 6
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
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 90.
Advice
• You are advised to spend 70 minutes on Section A and 50 minutes on Section B.
*JUN207405301*
IB/M/Jun20/E9 7405/3
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 This question is about emissions of oxides of nitrogen from petrol and diesel engines.
0 1 . 1 Explain how oxides of nitrogen are formed in engines.
[2 marks]
0 1 . 2 State why it is desirable to decrease emissions of oxides of nitrogen from vehicles.
[1 mark]
0 1 . 3 Modern diesel vehicles use diesel exhaust fluids, such as AdBlue, to decrease
emissions of oxides of nitrogen.
AdBlue reacts with water in the hot exhaust gases to form ammonia.
In the presence of a catalyst the ammonia reacts with oxides of nitrogen to form
nitrogen and water.
Give the oxidation state of nitrogen in each of NO2, NH3 and N2
Complete the equation for the reaction between NO2 and NH3
[2 marks]
Oxidation state of nitrogen in
NO2 NH3 N2
Equation
NO2 + NH3 → N2 + H2O
*02*
IB/M/Jun20/7405/3
, 3
Do not write
outside the
0 1 . 4 Petrol vehicles have a catalytic converter which decreases emissions of oxides of box
nitrogen.
Platinum in the catalytic converter acts as a heterogeneous catalyst.
State the meaning of the term heterogeneous catalyst.
[2 marks]
0 1 . 5 Some carbon particulates are also formed in both diesel and petrol vehicles.
Explain why carbon particulates are formed.
[1 mark]
8
Turn over for the next question
Turn over ►
*03*
IB/M/Jun20/7405/3
, 4
Do not write
outside the
0 2 This question is about oxides. box
0 2 . 1 Sodium oxide forms a solution with a higher pH than magnesium oxide when equal
amounts, in moles, of each oxide are added separately to equal volumes of water.
State why both oxides form alkaline solutions.
Suggest why sodium oxide forms a solution with a higher pH than the solution formed
from magnesium oxide.
[2 marks]
0 2 . 2 Give an equation for the reaction between phosphorus(V) oxide and water.
[1 mark]
0 2 . 3 In the Contact process, sulfur(IV) oxide is converted into sulfur(VI) oxide using
vanadium(V) oxide as a catalyst.
Give two equations to show how the vanadium(V) oxide acts as a catalyst in this
process.
[2 marks]
Equation 1
Equation 2 5
*04*
IB/M/Jun20/7405/3
