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A-level CHEMISTRY
Paper 2 Organic and Physical Chemistry
Monday 19 June 2023 Afternoon Time allowed: 2 hours
Materials
For Examiner’s Use
For this paper you must have:
the Periodic Table/Data Booklet, provided as an insert (enclosed) Questio Mark
a ruler with millimetre measurements n
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 6
write 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 8
answer(s). 9
All working must be shown.
TOTAL
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 105.
7405/2
,7405/2
, 2
Do not write
outside the
Answer all questions in the spaces box
provided.
0 1 This question is about rates of reaction.
Figure 1 shows apparatus used to measure the rate of reaction when an
acid reacts with an excess of solid sodium hydrogencarbonate, NaHCO3
When different monoprotic organic acids are used, the rates at which gas
escapes can be used to compare the strengths of the acids.
A timer is started when the NaHCO3 is added to the
acid and the mass of CO2 gas lost is recorded at
regular intervals.
(It is assumed that any change in mass is due to the loss of CO2)
Figure 1
0 1 .1 Suggest a reason why using a conical flask instead of a beaker would
give more accurate results in this experiment.
[1 mark]
IB/M/
Jun23/7405/2
, 3
Do not write
outside the
Figure 2 shows the results of this experiment when 25.0 cm3 of a box
2.23 mol dm–3 solution of ethanoic acid reacts with an excess of
NaHCO3
Figure 2
0 1
.2 Use Figure 2 to calculate the rate of reaction at 2
minutes. Deduce the units of your calculated rate.
[3 marks]
Rate Units
0 1 .3 Chloroethanoic acid is a stronger acid than ethanoic acid.
Sketch, on Figure 2, the curve you would expect when 25.0 cm 3 of a 2.23
mol dm–3 solution of chloroethanoic acid reacts with an excess of
NaHCO3
Suggest why chloroethanoic acid is a stronger acid than ethanoic acid.
[3 marks]
7
*03
IB/M/
* Jun23/7405/2