AQA A-Level Chemistry Paper 2 Predicted Paper 2023 questions and answers – Organic and Physical Chemistry

AQA

A-Level Chemistry 

Paper 2 – Organic and Physical Chemistry Predicted Paper 2023

Name ……………………………………………………………………

Date …………………

2 hours allowed

You should have access to the AQA insert (periodic table and data sheet) to help with answering the questions.

Grade boundaries

These are VERY rough guesses! Getting a C on this paper does not guarantee you the same mark in the exam.

• A* - 90

• A – 80

• B – 70

• C – 60

• D – 50

• E - 40

01 Esters have many important commercial uses such as solvents and artificial flavorings in food.

A mixture was prepared using 2.00 mol of CH3COOH, 3.00 mol of methanol and 7.00 mol of water.

The mixture was left to reach equilibrium according to the following equation at T1.

CH3COOH + CH3OH ⇌ CH3COOCH3+ H2O ΔH = -50 kJ/mol

The equilibrium mixture contains 0.85 moles of the ester.

01.1 Write an expression for the equilibrium constant Kc for this reaction.

[1 mark]

01.2 Calculate the value of Kc.

Explain why this Kc value has no units.

[4 marks]

01.3 The equilibrium mixture was allowed to reach the equilibrium at a higher temperature, T2 without changing the volume of the container.

State whether the value of Kc will increase, decrease or stay the same.

Explain your answer.

[4 marks]

02 A chemist investigates the rate of the iodoform reaction.

Methyl ketone (RCOCH3) reacts with iodine (I2) in the presence of aqueous NaOH.

The result of the investigation is shown below.

Table 01

Experiment [RCOCH3(aq)]

/ moldm-3 [NaOH(aq)]

/ moldm-3 Initial rate

/ moldm-3s-1

01 2.50×10-3 3.00×10-2 3.24×10-9

02 5.00×10-3 3.00×10-2 6.48×10-9

03 5.00×10-3 7.50×10-2 1.62×10-8

02.1 Deduce the order of the reaction with respect to I2, RCOCH3 and NaOH.

[3 marks]

02.2 State the overall rate equation for this reaction.

[1 mark]

02.3 Use the data from the experiment 01 to calculate the value for the rate constant k for this reaction. Deduce the units of k.

[2 marks]

k =  units = 

03 Formation of DNA is an important polymerization that occurs within living organisms.

The DNA has a double helix structure that consists of two strands linked together.

03.1 Identify the type of bonding that exists between the

[2 marks]

i. Phosphate and sugar groups within a DNA strand.

ii. Different bases on the two strands

03.2 Identify the four nitrogenous bases in DNA.

[2 marks]