Exam (elaborations)
AQA A-level CHEMISTRY Paper 2 QP 2023
- Course
- AQA CHEMISTRY 2023
- Institution
- AQA CHEMISTRY 2023
AQA A-level CHEMISTRY Paper 2 QP 2023
[Show more]
Content preview
AQA A-level CHEMISTRY Paper 2 QP 2023Please 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 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) 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.
5
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write outside 6
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 8
this book. Write the question number against your answer(s).
• All working must be shown. 9
• Do all rough work in this book. Cross through any work you do not want to TOTAL
be marked.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 105.
*Jun237405201*
IB/M/Jun23/E8 7405/2
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
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]
*02*
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 cm3 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
Turn over ►
*03*
IB/M/Jun23/7405/2
, 4
Do not write
outside the
0 2 A and B react together in the presence of an acid catalyst. box
A(aq) + 2 B(aq) → C(aq) + D(aq)
The rate equation for this reaction is
rate = k[B]2[H+]
Table 1 shows how the values of the relative initial rate vary with different
concentrations of each reagent at the same temperature.
Table 1
[A] [B] [H+] Relative initial
Experiment
/ mol dm–3 / mol dm–3 / mol dm–3 rate
1 0.40 0.20 0.10 1.00
2 0.50 0.20 0.10
3 0.40 0.10 0.64
4 0.50 0.30 0.06
0 2 . 1 Complete Table 1 by calculating the missing values.
[3 marks]
0 2 . 2 A suggested mechanism for the reaction is shown.
Step 1 B + H+ → BH+
Step 2 BH+ + B → B2H+
Step 3 B2H+ + A → C + D
Deduce the rate-determining step for this reaction.
Give a reason for your answer.
[2 marks]
Rate-determining step
Reason
5
*04*
IB/M/Jun23/7405/2
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Firstrate. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for CA$18.87. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
77254 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now