AQA A-Level Chemistry Paper 3, 2019
Every question from AQA A-Level Chemistry Paper 3, 2019: 35 questions, 90 marks, each with its mark scheme and topic.
- Question 1 13 marks
Write an ionic equation for the thiosulfate-acid reaction, explain the pollution effect and reaction of sulfur dioxide, describe the shape of water, and design an experiment investigating the effect of temperature on reaction rate.
Physical Chemistry · Inorganic Chemistry · Required Practicals · 3.1.2 Amount of Substance · 3.1.3 Bonding · 3.1.5 Kinetics · 3.2.4 Properties of Period 3 Elements and Their Oxides · Required Practical 3: Investigation of how the rate of a reaction changes
- Question 2 15 marks
Demonstrate knowledge of sulfuric acid by drawing its displayed formula, writing dissociation equations, describing standard solution preparation, calculating Ka, and explaining pH change on adding sodium sulfate.
Physical Chemistry · Required Practicals · 3.1.2 Amount of Substance · 3.1.3 Bonding · 3.1.6 Chemical Equilibria, Le Chatelier's Principle and Kc · 3.1.12 Acids and Bases · Required Practical 1: Making up a volumetric solution
- Question 3 17 marks
Analyse the setup and data for electrochemical cells, including identifying components, plotting an Ecell graph against ln([Zn2+]/[Cu2+]), and calculating temperature and electrode potentials.
Physical Chemistry · Required Practicals · 3.1.11 Electrode Potentials · Required Practical 8: Measuring the EMF of an electrochemical cell
- Question 4 9 marks
State the mechanism and explain the stereochemical outcome of the reaction between ethanal and potassium cyanide, then give the conditions to dehydrate the product and draw its polymer.
Organic Chemistry · 3.3.1 Introduction to Organic Chemistry · 3.3.4 Alkenes · 3.3.5 Alcohols · 3.3.7 Optical Isomerism · 3.3.8 Aldehydes and Ketones
- Question 5 6 marks
Determine the reaction equations, mean concordant titre, titration endpoint colour change, required apparatus, and percentage weighing uncertainty for an iron-manganate(VII) redox titration.
Physical Chemistry · Inorganic Chemistry · Required Practicals · 3.1.2 Amount of Substance · 3.1.7 Oxidation, Reduction and Redox Equations · 3.2.5 Transition Metals · Required Practical 1: Making up a volumetric solution
- Question 6 1 mark
Determine which volume and concentration of sodium hydroxide reacts completely with 7.5 g of a diprotic acid.
Physical Chemistry · 3.1.2 Amount of Substance
- Question 7 1 mark
Determine the amount in moles of lead(II) iodide formed when given volumes and concentrations of lead(II) nitrate and potassium iodide are reacted.
Physical Chemistry · 3.1.2 Amount of Substance
- Question 8 1 mark
Calculate the enthalpy change for the oxidation of ammonia to nitrogen dioxide using Hess's law.
Physical Chemistry · 3.1.4 Energetics
- Question 9 1 mark
Identify which change to the reaction mixture shifts the equilibrium to produce a higher concentration of sulfur trioxide.
Physical Chemistry · 3.1.6 Chemical Equilibria, Le Chatelier's Principle and Kc
- Question 10 1 mark
Calculate the initial concentration of Q in experiment 2 using the given rate equation and initial rates data.
Physical Chemistry · 3.1.9 Rate Equations
- Question 11 1 mark
Calculate the mole fraction of sulfur trioxide at equilibrium given initial amounts of reactants and the total moles of gas at equilibrium.
Physical Chemistry · 3.1.2 Amount of Substance · 3.1.10 Equilibrium Constant Kp
- Question 12 1 mark
Identify which change increases the equilibrium yield of ammonia in the Haber process without affecting the value of the equilibrium constant Kp.
Physical Chemistry · 3.1.6 Chemical Equilibria, Le Chatelier's Principle and Kc · 3.1.10 Equilibrium Constant Kp
- Question 13 1 mark
Calculate the standard EMF of an electrochemical cell containing iron and copper electrodes using standard electrode potentials.
Physical Chemistry · 3.1.11 Electrode Potentials
- Question 14 1 mark
Identify which atom from H, He, Li, and Ne has the greatest first ionisation energy.
Physical Chemistry · Inorganic Chemistry · 3.1.1 Atomic Structure · 3.2.1 Periodicity
- Question 15 1 mark
Identify the correct observation when barium metal is added to an excess of water.
Inorganic Chemistry · 3.2.2 Group 2, The Alkaline Earth Metals
- Question 16 1 mark
Identify which salt forms a white precipitate with both aqueous silver nitrate and dilute sulfuric acid.
Inorganic Chemistry · Required Practicals · 3.2.2 Group 2, The Alkaline Earth Metals · 3.2.3 Group 7(17), The Halogens · Required Practical 4: Carry out simple test-tube reactions to identify Cations and Anions
- Question 17 1 mark
Identify which statement is not correct regarding the trends in properties of the hydrogen halides from HCl to HI.
Inorganic Chemistry · Physical Chemistry · 3.2.3 Group 7(17), The Halogens · 3.1.3 Bonding
- Question 18 1 mark
Identify the observation made when concentrated hydrochloric acid is added to an aqueous solution of copper(II) sulfate until no further change occurs.
Inorganic Chemistry · 3.2.5 Transition Metals · 3.2.6 Reactions of Ions in Aqueous Solution
- Question 19 1 mark
Identify the most suitable reagent for detecting the presence of carbonate ions in the presence of an excess of sulfate ions.
Inorganic Chemistry · Required Practicals · 3.2.2 Group 2, The Alkaline Earth Metals · Required Practical 4: Carry out simple test-tube reactions to identify Cations and Anions
- Question 20 1 mark
Identify the mechanism for the reaction of methylbenzene with a mixture of concentrated nitric acid and concentrated sulfuric acid.
Organic Chemistry · 3.3.1 Introduction to Organic Chemistry · 3.3.10 Aromatic Chemistry
- Question 21 1 mark
Identify which reaction mechanism is not used in the multi-step synthesis of benzyl ethanoate from methylbenzene.
Organic Chemistry · 3.3.1 Introduction to Organic Chemistry · 3.3.2 Alkanes · 3.3.3 Halogenoalkanes · 3.3.9 Carboxylic Acids and Derivatives · 3.3.14 Organic Synthesis
- Question 22 1 mark
Identify the compound formed when 1-phenylethanol is oxidized by acidified potassium dichromate(VI).
Organic Chemistry · 3.3.5 Alcohols · 3.3.8 Aldehydes and Ketones · 3.3.1 Introduction to Organic Chemistry
- Question 23 1 mark
Identify which row correctly matches the organic compound with the observations seen when reacted separately with sodium hydrogen carbonate, acidified potassium dichromate(VI), and Tollens' reagent.
Organic Chemistry · Required Practicals · 3.3.6 Organic Analysis · 3.3.8 Aldehydes and Ketones · Required Practical 6: Tests for alcohol, aldehyde, alkene and carboxylic acid
- Question 24 1 mark
Identify which compound is formed by the acid hydrolysis of phenylmethyl ethanoate.
Organic Chemistry · 3.3.1 Introduction to Organic Chemistry · 3.3.9 Carboxylic Acids and Derivatives
- Question 25 1 mark
Identify a suitable drying agent to dry a liquid sample of pentanoic acid from a list of options.
Organic Chemistry · Required Practicals · 3.3.9 Carboxylic Acids and Derivatives · Required Practical 10: Preparation of a pure organic liquid
- Question 26 1 mark
Identify the correct representation of part of the mechanism for the Friedel–Crafts acylation of benzene with propanoyl chloride.
Organic Chemistry · 3.3.10 Aromatic Chemistry · 3.3.9 Carboxylic Acids and Derivatives · 3.3.1 Introduction to Organic Chemistry
- Question 27 1 mark
Identify which compound cannot be formed when methylamine reacts with bromoethane by nucleophilic substitution.
Organic Chemistry · 3.3.11 Amines · 3.3.3 Halogenoalkanes
- Question 28 1 mark
Identify which polymer features hydrogen bonding between its chains from Kevlar, Polythene, PVC, and Terylene.
Organic Chemistry · Physical Chemistry · 3.1.3 Bonding · 3.3.12 Polymers
- Question 29 1 mark
Identify which chemical structure represents part of a peptide link in a protein.
Organic Chemistry · 3.3.13 Amino Acids, Proteins and DNA · 3.3.12 Polymers
- Question 30 1 mark
Identify the correct base pair in DNA and the number of hydrogen bonds between them.
Organic Chemistry · 3.3.13 Amino Acids, Proteins and DNA
- Question 31 1 mark
Identify which species or electrons are not responsible for the conduction of electricity.
Physical Chemistry · 3.1.3 Bonding
- Question 32 1 mark
Identify a likely reason why the direct hydration of ethene has largely replaced the fermentation method for industrial ethanol production.
Organic Chemistry · 3.3.5 Alcohols
- Question 33 1 mark
Identify which alkene reacts with hydrogen bromide to form 2-bromo-3-methylbutane as the major product.
Organic Chemistry · 3.3.1 Introduction to Organic Chemistry · 3.3.4 Alkenes
- Question 34 1 mark
Identify which compound can be purified by recrystallisation from a hot aqueous solution.
Organic Chemistry · Required Practicals · 3.3.9 Carboxylic Acids and Derivatives · 3.3.14 Organic Synthesis · Required Practical 12: Separation and purification techniques
- Question 35 1 mark
Identify the main species of aspartic acid present in an aqueous solution at pH = 14.
Organic Chemistry · 3.3.13 Amino Acids, Proteins and DNA