AS Chemistry Paper 2 – Organic and Physical Chemistry Predicted Paper 2023 with marking scheme attached.

AQA AS Chemistry Paper 2 – Organic and Physical Chemistry Predicted Paper 2023 with marking scheme attached. Name …………………………………………………………………… Date ………………… 1 hour 30 minutes allowed You should have access to the AQA insert (periodic table and data sheet) to help with answering the questions. You should spend around 65 minutes on section A and 25 minutes on section B. Grade boundaries These are VERY rough guesses! Getting a C on this paper does not guarantee you the same mark in the exam. • A – 80 • B – 70 • C – 60 • D – 50 • E - 40 SECTION A 01 A chemist carries out an investigation on the equilibrium system shown below. 2X(g) + Y(g) ⇌ 2Z(g) This reaction can be carried out so that the position of the equilibrium is completely on the right-hand side, at a temperature of 500°C and 2 atmosphere pressures in the presence of a V2O5 catalyst. Then the chemist carries out this reaction at a temperature of 500°C and 2 atmospheres pressure. He does not use the catalyst. 01.1 Predict the changes, if any to each of the following. i. Position of the equilibrium. [1 mark] ii. Rate of the backward reaction. [1 mark] 01.2 The chemist mixes together 2.00 × 10-3 mol X(g) and 4.00 × 10-3 mol Y(g) in a 1.00 dm3 container. At equilibrium, the mixture contains 3.00 × 10-4 mol of X(g). Calculate the equilibrium constant Kc, including units, if any, for the equilibrium. Give your answer to three significant figures. [5 marks] Kc = Units = 02.1 A 25 mL sample of NaOH is titrated to the end point with 15 mL of a 0.25 M HCl solution. What is the molarity of the NaOH solution? [1 mark] 02.2 Titration experiments use equipment with a measurement uncertainty. The uncertainty of the pipette which was used is ±0.04 cm3 while the uncertainty of the burette is ±0.05 cm3. Calculate the percentage uncertainty for the burette titre value of 25 cm3 and for the pipette volume of 15 cm3. [4 marks] % uncertainty pipette = % uncertainty titre = 03.1 Draw the structure of (E)-pent-3-en-2-ol. [1 mark] 03.2 The above compound was analysed using infrared (IR) spectroscopy. The IR spectrum contained a broad adsorption in the region of cm-1. What does that broad absorption indicate? [1 mark] 03.3 Draw one of the structural isomers for the above compound that is acyclic and contains a different functional group. [1 mark] 03.4 The structural isomers which are drawn in 03.3 have a lower boiling point than (E)-pent-3-en-2-ol. Explain why. [1 mark] 03.5 The following two compounds have similar molecular weights but have different boiling points. Identify the compound with the higher boiling point and explain why. [6 marks] Compound A Compound B 04 Alcohol P has a molecular formula of C6H12O. A student does an experiment to measure the enthalpy change of combustion, ΔHc, of alcohol P. Combustion of 4.40 g of the alcohol changes the temperature of 150 g of water from 25.2°C to 75.3°C. The specific heat capacity of water is 4.18 J g-1 K-1. 04.1 Calculate the enthalpy change of combustion, ΔHc, of alcohol P in kJ/mol. [3 marks] ΔHc = kJ/mol 04.2 Write an equation for the complete combustion of alcohol P. [1 mark]