OxfordAQA assesses experimental chemistry through written questions on Unit 5 as well as throughout Units 1 to 4. Candidates are expected to demonstrate deep familiarity with the 10 core laboratory procedures specified in the 9620 Practical Handbook.
Questions in Unit 5 often ask candidates to:
Unit 5 questions never exist in a vacuum. Every practical procedure is intertwined with underlying quantitative theory: RP1 titration calculations feed back into mole ratios; RP2 calorimetry ties into Hess's law cycles; RP8 rate experiments lead to Arrhenius activation energy derivations; and RP7 pH titrations evaluate buffer equilibria and weak acid Ka.
Click any guide below for full step-by-step procedures, apparatus diagrams, percentage uncertainty calculations, and exam-style worked examples:
Prepare a standard volumetric solution using weighing by difference, and perform accurate titrations to determine an unknown concentration.
Measure temperature change in a solution reaction using an insulated polystyrene cup calorimeter, and calculate molar enthalpy change.
Systematic qualitative test-tube reactions to identify Group 2 cations (Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺), ammonium ions, halides, sulfates, and carbonates.
Prepare and isolate a volatile organic liquid (e.g. oxidation of ethanol to ethanal) using Quickfit simple distillation glassware.
Diagnostic chemical tests to identify alcohols, aldehydes, alkenes and carboxylic acids. The halogenoalkane test is an extension beyond the four RP5 tests.
Construct electrochemical half-cells, measure cell potentials using a high-resistance voltmeter, and evaluate concentration effects.
Calibrate a digital pH meter, follow pH changes when a weak acid is titrated with a strong base and a strong acid with a weak base, identify equivalence points, and deduce weak acid Ka.
Continuous monitoring of reaction progress (gas syringe volume vs time) and initial rate methods (iodine clock reaction and disappearing cross with Arrhenius activation energy).
Qualitative test-tube analysis of aqueous metal ions (Fe²⁺, Cu²⁺, Al³⁺ and Fe³⁺; Cr³⁺ and Co²⁺ are beyond the OxfordAQA specification) using sodium hydroxide, ammonia, and carbonate.
Prepare aspirin by heating 2-hydroxybenzoic acid with ethanoic anhydride in a water bath, filter using Buchner suction filtration, recrystallise from the minimum volume of hot solvent, and test purity by melting point.
Each practical belongs to one spec section. Revise the notes pages in the last column before you do the practical. Unit 5 can test any practical.
| RP | 9620 practical | Spec | Unit | Notes pages |
|---|---|---|---|---|
| RP1 | Make a volumetric solution and carry out a simple acid-base titration | 3.1.2.5 | Unit 1 | Amount of Substance & Solution Calculations Balanced Equations and Calculations |
| RP2 | Measure an enthalpy change | 3.1.4.2 | Unit 1 | Energetics, Calorimetry & Hess Law Cycles |
| RP3 | Carry out simple test-tube reactions to identify cations (Group 2, NH₄⁺) and anions (halide ions, OH⁻, CO₃²⁻, SO₄²⁻) | 3.2.3.2 | Unit 1 | Group 2: The Alkaline Earth Metals Group 7: The Halogens |
| RP4 | Distil a product from a reaction | 3.3.5.2 | Unit 2 | Alcohols: Oxidation, Elimination and Tests |
| RP5 | Carry out tests for alcohols, aldehydes, alkenes and carboxylic acids | 3.3.6.1 | Unit 2 | Organic Analysis: Infrared Spectroscopy & Mass Spectrometry Alcohols: Oxidation, Elimination and Tests Alkenes: Structure, Electrophilic Addition & Polymers |
| RP6 | Measure the electromotive force (EMF) of an electrochemical cell | 3.1.9.1 | Unit 3 | Electrode Potentials & Electrochemical Cells |
| RP7 | Investigate how pH changes when a weak acid reacts with a strong base and when a strong acid reacts with a weak base | 3.1.10.5 | Unit 3 | Acids, Bases, Buffers & pH Curves |
| RP8 | Measure the rate of reaction by an initial rate method and a continuous monitoring method | 3.1.11.2 | Unit 4 | Rate Equations & Arrhenius Analysis Kinetics, Collision Theory & Catalysis |
| RP9 | Carry out simple test-tube reactions to identify transition metal ions in aqueous solution | 3.2.6.1 | Unit 3 | Reactions of Aqueous Ions (Metal-Aqua Complexes) Transition Metals & Complex Ions |
| RP10 | Prepare a pure organic solid and test its purity | 3.3.9.2 | Unit 4 | Carboxylic Acids & Acyl Derivatives Chromatography |