AQA AS CHEMISTRY 7404/2 Paper 2 Organic and Physical Chemistry Question Paper + Mark scheme [MERGED] June 2022

AQA

AS

CHEMISTRY

7404/2

Paper 2 Organic and Physical Chemistry

Question Paper + Mark scheme [MERGED]

June 2022

*JUN227404201*

IB/M/Jun22/E7 7404/2

For Examiner’s Use

Question Mark

1

2

3

4

5

6

7

Section B

TOTAL

Time allowed: 1 hour 30 minutes

Materials

For this paper you must have:

• the Periodic Table/Data Sheet, provided as an insert (enclosed)

• a ruler with millimetre measurements

• a scientific calculator, which you are expected to use where appropriate.

Instructions

• Use black ink or black ball-point pen.

• Fill in the boxes at the top of this page.

• Answer all questions.

• You must answer the questions in the spaces provided. Do not write outside

the box around each page or on blank pages.

• 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).

• 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 about 65 minutes on Section A and 25 minutes on Section B.

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

2

*02*

IB/M/Jun22/7404/2

Do not write

outside the

Section A box

Answer all questions in this section.

0 1 This question is about rates of reaction.

Potassium manganate(VII), KMnO4, reacts with sodium ethanedioate, Na2C2O4, in the

presence of dilute sulfuric acid.

2 MnO4

–(aq) + 16H+(aq) + 5C2O4

2–(aq) → 2 Mn2+(aq) + 8H2O(l) + 10CO2(g)

The reaction mixture is purple at the start and goes colourless when all the

MnO4

–(aq) ions have reacted.

The rate of reaction can be measured as 1000

t where t = the time taken for the mixture

to go colourless.

A student investigated how long it takes for this reaction mixture to go colourless at

different temperatures. The same concentrations and volumes of each reagent were

used in an experiment at each temperature. Table 1 shows the results.

Table 1

Temperature / C 32 38 44 54 67

Time t / s 155 85 50 22 9

1000

t

6.45 11.8 20.0 45.5

0 1 . 1 Complete Table 1.

[1 mark]

0 1 . 2 State the independent variable in this investigation.

[1 mark]

0 1 . 3 The student noticed that the temperature of each reaction mixture decreased during

each experiment.

Suggest how the student calculated the temperature values in Table 1.

[1 mark]

3

*03*

Turn over ►

IB/M/Jun22/7404/2

Do not write

outside the

box Use the data in Table 1 to plot a graph of 1000

t against temperature.

[3 marks]

0 1 . 4

0 1 . 5 Use your graph in Question 01.4 to find the time taken for the mixture to go colourless

at 60 °C

Show your working.

[1 mark]

Time t s

4

*04*

IB/M/Jun22/7404/2

Do not write

outside the

box 0 1 . 6 The investigation shows that increasing the temperature causes the rate of reaction to

increase.

Explain why a small increase in temperature causes a large increase in the rate of

reaction.

[2 marks]