Source: https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-5-required-practical-electrolysis

[Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [GCSE](https://senecalearning.com/en-gb/revision-notes/gcse.md) › [Chemistry](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry.md) › [AQA](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa.md) › [Higher](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher.md) › Required Practical: Electrolysis

# Required Practical: Electrolysis

Chemistry: AQA GCSE Higher, topic 4.4.5

## Electrolysis of Aqueous Solutions Using Inert Electrodes

This experiment investigates which ions are discharged during the electrolysis of aqueous ionic solutions using inert electrodes, and identifies the products formed at each electrode.

### Apparatus and materials

![Apparatus and materials](https://image-v2.cdn.app.senecalearning.com/2025-06/ef3392fb-65a2-43f4-acf6-7324b49425e0/Electrolysis--1600x1600.jpg)

- DC power supply
- Two inert electrodes (carbon or platinum)
- Beaker
- Test tubes or gas collection tubes
- Retort stand and clamps
- Leads and crocodile clips
- Range of aqueous solutions (such as copper(II) sulfate, copper(II) chloride, sodium chloride, sodium nitrate, sodium bromide)
- Splints and litmus paper for gas testing

### Method

![Method](https://image-v2.cdn.app.senecalearning.com/2025-10/7ef245ec-4d08-4534-820f-23c2b8cf49d8/testtube.png)

- Assemble the electrolysis apparatus: 
 - Connect the electrodes to the DC power pack, ensuring one electrode is attached to each terminal.
- Pour an aqueous solution into the beaker so that both electrodes are submerged.
- Switch on the power supply and allow electrolysis to happen for several minutes.
- Observe any visible changes, such as gas bubbles or metal deposition on the electrodes.

### Method (continuation)

![Method (continuation)](https://image-v2.cdn.app.senecalearning.com/2025-10/587fb79b-2d4b-4c25-8ec1-929a74928c72/splint.png)

- Collect any gases formed using inverted test tubes.
- Test the gases using the following standard gas tests:
 - Hydrogen: a lighted splint produces a **squeaky pop**
 - Oxygen: a **glowing splint** relights
 - Chlorine: damp blue **litmus paper** turns red, then bleaches white
- Record all observations, including the identity of gases and any metal deposits.
- Repeat for at least five different electrolyte solutions.

### Variables

![Variables](https://image-v2.cdn.app.senecalearning.com/2023-01/23faeead-75dd-4f42-b71b-e859a2c2968a/pawan-parihar-Q7ngZ0oKIfc-unsplash.jpg)

- Independent variable: 
 - Type of aqueous solution used (e.g., copper sulfate, sodium chloride)
- Dependent variable: 
 - Products formed at each electrode
- Control variables: 
 - Current supplied, size and type of electrodes, volume and concentration of solution, and duration of electrolysis

### Hazards and safety precautions

![Hazards and safety precautions](https://image-v2.cdn.app.senecalearning.com/2020-06/00f334f2-2831-468f-a750-e9633d31d684/danger-sign-.jpg)

- Copper(II) compounds: 
 - Harmful if ingested; avoid contact with skin.
- Chlorine gas: 
 - Toxic; carry out experiments in a well-ventilated room or fume cupboard.
- Electric current: 
 - Avoid contact with solutions while the circuit is live.
- Always wear safety goggles and a lab coat, and wash hands after handling chemicals.

### Analysing the results

![Analysing the results](https://image-v2.cdn.app.senecalearning.com/2018-09/9501d93b-df95-4414-8980-aa94bf5888af/scoreboard-sports-score-result-.jpg)

- After electrolysis, identify which products appeared at the anode and cathode for each solution. Compare the outcomes with your original hypothesis.
- Typical observations might include:
 - Copper(II) sulfate: copper metal at the cathode; oxygen at the anode.
 - Sodium chloride: hydrogen at the cathode; chlorine at the anode.

## Test yourself on Required Practical: Electrolysis

- A student collects a gas at the cathode during electrolysis of sodium chloride solution and wants to confirm it is hydrogen. Which test would confirm this?
- Why should chlorine gas produced during electrolysis be handled in a well-ventilated room or fume cupboard?
- What is the dependent variable in this investigation?
- What forms at the cathode during the electrolysis of copper(II) sulfate solution using inert electrodes?
- A student collects a gas at the anode during electrolysis of copper(II) sulfate solution. A glowing splint relights in the gas. What is the gas?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/e39e7f70-d100-11e7-9b85-bbf8589a9044/section/03c83416-3683-4b86-bd3e-aa393ad022e7/session)

- Previous topic: [4.4.4 Electrolysis of Aqueous Solutions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-4-electrolysis-of-aqueous-solutions.md)
- Next topic: [4.4.6 Half Equations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-6-half-equations.md)

## Chemistry: AQA GCSE Higher contents

### 1 Atomic Structure
- 1.1 Atoms & Elements
  - [1.1.1 Elements & Compounds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-1-elements-and-compounds.md)
  - [1.1.2 Chemical Formula](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-2-chemical-formula.md)
  - [1.1.3 Chemical Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-3-chemical-reactions.md)
  - [1.1.4 Chemical Equations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-4-chemical-equations.md)
  - [1.1.5 Mixtures](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-5-mixtures.md)
  - [1.1.6 Separating Mixtures](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-6-separating-mixtures.md)
  - [1.1.7 Separating Mixtures 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-7-separating-mixtures-2.md)
  - [1.1.8 Model of the Atom](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-8-model-of-the-atom.md)
  - [1.1.9 Sub-Atomic Particles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-9-sub-atomic-particles.md)
  - [1.1.10 Atom Size](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-10-atom-size.md)
  - [1.1.11 Atomic Number](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-11-atomic-number.md)
  - [1.1.12 Atomic Number - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-12-atomic-number-calculations.md)
  - [1.1.13 Isotopes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-13-isotopes.md)
  - [1.1.14 Isotopes HyperLearning](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-14-isotopes-hyperlearning.md)
  - [1.1.15 Isotopes - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-15-isotopes-calculations.md)
  - [1.1.16 Relative Atomic Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-16-relative-atomic-mass.md)
  - [1.1.17 Electron Structure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-17-electron-structure.md)
  - [1.1.18 Periodic Table](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-18-periodic-table.md)
  - [1.1.19 The History of the Periodic Table](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-19-the-history-of-the-periodic-table.md)
  - [1.1.20 Metals & Non-Metals](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-20-metals-and-non-metals.md)
  - [1.1.21 Noble Gases](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-21-noble-gases.md)
  - [1.1.22 Displacement Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-22-displacement-reaction.md)
  - [1.1.23 Halogens](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-23-halogens.md)
  - [1.1.24 Alkali Metals](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-24-alkali-metals.md)
  - [1.1.25 Alkali Metals - Properties](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-25-alkali-metals-properties.md)
  - [1.1.26 Transition Metals](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-26-transition-metals.md)
  - [1.1.27 Transition Metals - Special Properties](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-27-transition-metals-special-properties.md)
  - [1.1.28 End of Topic Test - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-28-end-of-topic-test-atomic-structure.md)
  - [1.1.29 Grade 9 - Atoms & Elements](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-29-grade-9-atoms-and-elements.md)
  - [1.1.30 Exam-Style Questions - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-30-exam-style-questions-atomic-structure.md)
  - [1.1.31 Application Questions - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-31-application-questions-atomic-structure.md)
  - [1.1.32 Diagnostic Misconceptions - Balancing Equations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-32-diagnostic-misconceptions-balancing-equations.md)
  - [1.1.33 Diagnostic Misconceptions - Isotopes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/1-1-33-diagnostic-misconceptions-isotopes.md)

### 2 Chemical Bonding
- 2.1 Chemical Bonds
  - [2.1.1 Types of Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-1-types-of-bonds.md)
  - [2.1.2 Ions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-2-ions.md)
  - [2.1.3 Ionic Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-3-ionic-bonds.md)
  - [2.1.4 Ionic Compounds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-4-ionic-compounds.md)
  - [2.1.5 Empirical Formulae](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-5-empirical-formulae.md)
  - [2.1.6 Covalent Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-6-covalent-bonds.md)
  - [2.1.7 Metallic Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-7-metallic-bonds.md)
  - [2.1.8 Covalent Bond Examples](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-8-covalent-bond-examples.md)
  - [2.1.9 Representing Covalent Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-9-representing-covalent-bonds.md)
  - [2.1.10 Dots-And-Cross Diagrams](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-10-dots-and-cross-diagrams.md)
  - [2.1.11 Dots-And-Cross Diagrams 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-11-dots-and-cross-diagrams-2.md)
  - [2.1.12 Exam-Style Questions - Chemical Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-1-12-exam-style-questions-chemical-bonds.md)
- 2.2 States of Matter
  - [2.2.1 States of Matter](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-1-states-of-matter.md)
  - [2.2.2 Simple Sphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-2-simple-sphere.md)
  - [2.2.3 Changing State](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-3-changing-state.md)
  - [2.2.4 Changing State 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-4-changing-state-2.md)
  - [2.2.5 Changing State HyperLearning](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-5-changing-state-hyperlearning.md)
  - [2.2.6 State Symbols](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-6-state-symbols.md)
  - [2.2.7 Exam-Style Questions - States of Matter](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-7-exam-style-questions-states-of-matter.md)
  - [2.2.8 Diagnostic Misconceptions - Particles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-2-8-diagnostic-misconceptions-particles.md)
- 2.3 Chemical Properties
  - [2.3.1 Ionic Compounds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-1-ionic-compounds.md)
  - [2.3.2 Chemical Properties of Ionic Compounds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-2-chemical-properties-of-ionic-compounds.md)
  - [2.3.3 Small Molecules](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-3-small-molecules.md)
  - [2.3.4 Chemical Properties of Small Molecules](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-4-chemical-properties-of-small-molecules.md)
  - [2.3.5 Molecular Forces - Polymers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-5-molecular-forces-polymers.md)
  - [2.3.6 Molecular Forces - Polypropene](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-6-molecular-forces-polypropene.md)
  - [2.3.7 Giant Covalent Structures](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-7-giant-covalent-structures.md)
  - [2.3.8 Metals](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-8-metals.md)
  - [2.3.9 Alloys](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-9-alloys.md)
  - [2.3.10 Conductors](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-10-conductors.md)
  - [2.3.11 Carbon Structures - Diamond](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-11-carbon-structures-diamond.md)
  - [2.3.12 Carbon Structures - Graphite](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-12-carbon-structures-graphite.md)
  - [2.3.13 Carbon Structures - Graphene](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-13-carbon-structures-graphene.md)
  - [2.3.14 Carbon Structures - Fullerenes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-14-carbon-structures-fullerenes.md)
  - [2.3.15 Carbon Structures - Summary](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-15-carbon-structures-summary.md)
  - [2.3.16 Clumps](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-16-clumps.md)
  - [2.3.17 Nanoparticles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-17-nanoparticles.md)
  - [2.3.18 Nanotechnology](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-18-nanotechnology.md)
  - [2.3.19 Nanotechnology 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-19-nanotechnology-2.md)
  - [2.3.20 Surface Area to Volume Ratio](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-20-surface-area-to-volume-ratio.md)
  - [2.3.21 Nanotechnology Uses](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-21-nanotechnology-uses.md)
  - [2.3.22 End of Topic Test - Chemical Bonding](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-22-end-of-topic-test-chemical-bonding.md)
  - [2.3.23 Grade 9 - Bonding & Structure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-23-grade-9-bonding-and-structure.md)
  - [2.3.24 Exam-Style Questions - Allotropes of Carbon](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-24-exam-style-questions-allotropes-of-carbon.md)
  - [2.3.25 Diagnostic Misconceptions - Conducting Electricity](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-25-diagnostic-misconceptions-conducting-electricity.md)
  - [2.3.26 Diagnostic Misconceptions - Small Molecules](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-26-diagnostic-misconceptions-small-molecules.md)
  - [2.3.27 Diagnostic Misconceptions - Drawing Polymers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/2-3-27-diagnostic-misconceptions-drawing-polymers.md)

### 3 Quantitative Chemistry
- 3.1 Chemical Measurements
  - [3.1.1 Conservation of Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-1-conservation-of-mass.md)
  - [3.1.2 Relative Formula Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-2-relative-formula-mass.md)
  - [3.1.3 Calculating Relative Formula Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-3-calculating-relative-formula-mass.md)
  - [3.1.4 Relative Formula Mass - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-4-relative-formula-mass-calculations.md)
  - [3.1.5 Changing Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-5-changing-mass.md)
  - [3.1.6 Measuring Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-6-measuring-mass.md)
  - [3.1.7 Equations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-7-equations.md)
  - [3.1.8 Empirical Formula](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-8-empirical-formula.md)
  - [3.1.9 Introducing Moles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-9-introducing-moles.md)
  - [3.1.10 Relative Formula Mass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-10-relative-formula-mass.md)
  - [3.1.11 Amounts of Substance](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-11-amounts-of-substance.md)
  - [3.1.12 Moles to Balance Equations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-12-moles-to-balance-equations.md)
  - [3.1.13 Limiting Reactants](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-13-limiting-reactants.md)
  - [3.1.14 Concentration of Solutions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-14-concentration-of-solutions.md)
  - [3.1.15 Moles - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-15-moles-calculations.md)
  - [3.1.16 Percentage Yield](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-16-percentage-yield.md)
  - [3.1.17 Calculating Yield](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-17-calculating-yield.md)
  - [3.1.18 Percentage Yield - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-18-percentage-yield-calculations.md)
  - [3.1.19 Moles & Yield](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-19-moles-and-yield.md)
  - [3.1.20 Moles & Yield 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-20-moles-and-yield-2.md)
  - [3.1.21 Atom Economy](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-21-atom-economy.md)
  - [3.1.22 Reaction Pathway](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-22-reaction-pathway.md)
  - [3.1.23 Atom Economy - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-23-atom-economy-calculations.md)
  - [3.1.24 Concentrations of Solute](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-24-concentrations-of-solute.md)
  - [3.1.25 Calculating the Amount of  Solute](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-25-calculating-the-amount-of-solute.md)
  - [3.1.26 Amount of Substance in Relation to Volumes and Gas](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-26-amount-of-substance-in-relation-to-volumes-and-gas.md)
  - [3.1.27 Concentrations & Amounts - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-27-concentrations-and-amounts-calculations.md)
  - [3.1.28 Empirical Formula - Calculations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-28-empirical-formula-calculations.md)
  - [3.1.29 End of Topic Test - Quant Chemistry](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-29-end-of-topic-test-quant-chemistry.md)
  - [3.1.30 Grade 9 - Quantitative Chemistry](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-30-grade-9-quantitative-chemistry.md)
  - [3.1.31 Exam-Style Questions - Moles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-31-exam-style-questions-moles.md)
  - [3.1.32 Diagnostic Misconceptions - Calculating RFM](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-32-diagnostic-misconceptions-calculating-rfm.md)
  - [3.1.33 Diagnostic Misconceptions - Moles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/3-1-33-diagnostic-misconceptions-moles.md)

### 4 Chemical Changes
- 4.1 Acids, Alkalis & Redox Reactions
  - [4.1.1 Acids & Alkalis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-1-1-acids-and-alkalis.md)
  - [4.1.2 Redox Reactions - Oxidation](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-1-2-redox-reactions-oxidation.md)
  - [4.1.3 Redox Reactions - Metal Oxide](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-1-3-redox-reactions-metal-oxide.md)
- 4.2 Reactivity of Metals
  - [4.2.1 Reactivity Diagram](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-1-reactivity-diagram.md)
  - [4.2.2 Displacement Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-2-displacement-reactions.md)
  - [4.2.3 Displacement Reactions - Halogens](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-3-displacement-reactions-halogens.md)
  - [4.2.4 Reactions with Water](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-4-reactions-with-water.md)
  - [4.2.5 Reactions with Acid](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-5-reactions-with-acid.md)
  - [4.2.6 Reactivity Tests](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-6-reactivity-tests.md)
  - [4.2.7 Reactivity Tests 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-7-reactivity-tests-2.md)
  - [4.2.8 Extraction of Metals](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-8-extraction-of-metals.md)
  - [4.2.9 Exam-Style Questions - Displacement Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-2-9-exam-style-questions-displacement-reactions.md)
- 4.3 Reactions of Acids
  - [4.3.1 Reactions of Metals with Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-1-reactions-of-metals-with-acids.md)
  - [4.3.2 Redox Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-2-redox-reactions.md)
  - [4.3.3 Neutralisation of Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-3-neutralisation-of-acids.md)
  - [4.3.4 Soluble Salts](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-4-soluble-salts.md)
  - [4.3.5 Required Practical: Separating Mixtures](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-5-required-practical-separating-mixtures.md)
  - [4.3.6 The pH Scale](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-6-the-ph-scale.md)
  - [4.3.7 Numerical pH Scale](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-7-numerical-ph-scale.md)
  - [4.3.8 Measuring pH](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-8-measuring-ph.md)
  - [4.3.9 Neutralisation & Titrations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-9-neutralisation-and-titrations.md)
  - [4.3.10 Neutralisation & Titrations 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-10-neutralisation-and-titrations-2.md)
  - [4.3.11 Neutralisation & Titrations 3](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-11-neutralisation-and-titrations-3.md)
  - [4.3.12 Neutralisation & Titrations 4](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-12-neutralisation-and-titrations-4.md)
  - [4.3.13 Strong and Weak Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-13-strong-and-weak-acids.md)
  - [4.3.14 Required Practical: Titration](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-3-14-required-practical-titration.md)
- 4.4 Electrolysis
  - [4.4.1 Electrolysis Process](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-1-electrolysis-process.md)
  - [4.4.2 Molten Ionic Compound](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-2-molten-ionic-compound.md)
  - [4.4.3 Metal Extraction](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-3-metal-extraction.md)
  - [4.4.4 Electrolysis of Aqueous Solutions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-4-electrolysis-of-aqueous-solutions.md)
  - [4.4.5 Required Practical: Electrolysis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-5-required-practical-electrolysis.md)
  - [4.4.6 Half Equations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-6-half-equations.md)
  - [4.4.7 End of Topic Test - Chemical Changes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-7-end-of-topic-test-chemical-changes.md)
  - [4.4.8 Grade 9 - Chemical Changes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-8-grade-9-chemical-changes.md)
  - [4.4.9 Exam-Style Questions - Electrolysis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/4-4-9-exam-style-questions-electrolysis.md)

### 5 Energy Changes
- 5.1 Exothermic & Endothermic Reactions
  - [5.1.1 Energy Conservation](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-1-energy-conservation.md)
  - [5.1.2 Exothermic Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-2-exothermic-reactions.md)
  - [5.1.3 Endothermic Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-3-endothermic-reactions.md)
  - [5.1.4 Required Practical: Temperature Changes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-4-required-practical-temperature-changes.md)
  - [5.1.5 Reaction Profiles Requirements](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-5-reaction-profiles-requirements.md)
  - [5.1.6 Reaction Profiles](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-6-reaction-profiles.md)
  - [5.1.7 Reaction Profiles - Catalysed vs Uncatalysed](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-7-reaction-profiles-catalysed-vs-uncatalysed.md)
  - [5.1.8 Reaction Profiles - Chemical Bonds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-8-reaction-profiles-chemical-bonds.md)
  - [5.1.9 Diagnostic Misconceptions - Source of Energy](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-1-9-diagnostic-misconceptions-source-of-energy.md)
- 5.2 Chemical Cells & Fuel Cells
  - [5.2.1 Chemical Cells](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-1-chemical-cells.md)
  - [5.2.2 Changing Voltage Output](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-2-changing-voltage-output.md)
  - [5.2.3 Batteries](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-3-batteries.md)
  - [5.2.4 Charging of Cells](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-4-charging-of-cells.md)
  - [5.2.5 Fuel Cells](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-5-fuel-cells.md)
  - [5.2.6 Hydrogen Fuel Cell](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-6-hydrogen-fuel-cell.md)
  - [5.2.7 Hydrogen as an Alternative](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-7-hydrogen-as-an-alternative.md)
  - [5.2.8 End of Topic Test - Energy Changes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-8-end-of-topic-test-energy-changes.md)
  - [5.2.9 Grade 9 - Energy Changes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-9-grade-9-energy-changes.md)
  - [5.2.10 Exam-Style Questions - Fuel Cells](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/5-2-10-exam-style-questions-fuel-cells.md)

### 6 The Rate & Extent of Chemical Change
- 6.1 Rate of Reaction
  - [6.1.1 Chemical Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-1-chemical-reactions.md)
  - [6.1.2 Plotting Reaction Rates](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-2-plotting-reaction-rates.md)
  - [6.1.3 Required Practical: Effect of Concentration](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-3-required-practical-effect-of-concentration.md)
  - [6.1.4 Collision Theory](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-4-collision-theory.md)
  - [6.1.5 Key Factors of Rate of Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-5-key-factors-of-rate-of-reaction.md)
  - [6.1.6 Catalysts](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-6-catalysts.md)
  - [6.1.7 Catalysts in Industry](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-1-7-catalysts-in-industry.md)
- 6.2 Reversible Reactions
  - [6.2.1 Reversible Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-1-reversible-reactions.md)
  - [6.2.2 Dynamic Equilibrium](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-2-dynamic-equilibrium.md)
  - [6.2.3 Conditions and Equilibrium](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-3-conditions-and-equilibrium.md)
  - [6.2.4 Equilibrium Position - Temperature](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-4-equilibrium-position-temperature.md)
  - [6.2.5 Equilibrium Position - Pressure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-5-equilibrium-position-pressure.md)
  - [6.2.6 Equilibrium Position - Concentration](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-6-equilibrium-position-concentration.md)
  - [6.2.7 End of Topic Test - Rates of Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-7-end-of-topic-test-rates-of-reaction.md)
  - [6.2.8 Grade 9 - Rate & Extent of Chemical Change](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-8-grade-9-rate-and-extent-of-chemical-change.md)
  - [6.2.9 Exam-Style Questions - Reversible Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-9-exam-style-questions-reversible-reactions.md)
  - [6.2.10 Diagnostic Misconceptions - Temperature](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-10-diagnostic-misconceptions-temperature.md)
  - [6.2.11 Diagnostic Misconceptions - Pressure](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-11-diagnostic-misconceptions-pressure.md)
  - [6.2.12 Diagnostic Misconceptions - Concentration](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-12-diagnostic-misconceptions-concentration.md)
  - [6.2.13 Diagnostic Misconceptions - Catalysts](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/6-2-13-diagnostic-misconceptions-catalysts.md)

### 7 Organic Chemistry
- 7.1 Carbon Compounds
  - [7.1.1 Crude Oil](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-1-crude-oil.md)
  - [7.1.2 Properties of Hydrocarbons](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-2-properties-of-hydrocarbons.md)
  - [7.1.3 Alkanes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-3-alkanes.md)
  - [7.1.4 Smallest Alkanes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-4-smallest-alkanes.md)
  - [7.1.5 Fractional Distillation](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-5-fractional-distillation.md)
  - [7.1.6 Process of Fractional Distillation](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-6-process-of-fractional-distillation.md)
  - [7.1.7 Homologous Series](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-7-homologous-series.md)
  - [7.1.8 Burning Hydrocarbons](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-8-burning-hydrocarbons.md)
  - [7.1.9 Heavy Fractions of Crude Oil](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-9-heavy-fractions-of-crude-oil.md)
  - [7.1.10 Cracking](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-10-cracking.md)
  - [7.1.11 Uses of Alkenes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-11-uses-of-alkenes.md)
  - [7.1.12 Exam-Style Questions - Organic Compounds](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-1-12-exam-style-questions-organic-compounds.md)
- 7.2 Alkenes & Alcohols
  - [7.2.1 Structure of Alkenes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-1-structure-of-alkenes.md)
  - [7.2.2 The Shortest Alkenes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-2-the-shortest-alkenes.md)
  - [7.2.3 Reactions of Alkenes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-3-reactions-of-alkenes.md)
  - [7.2.4 Types of Alkene Reactions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-4-types-of-alkene-reactions.md)
  - [7.2.5 Alcohols](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-5-alcohols.md)
  - [7.2.6 The Smallest Alcohols](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-6-the-smallest-alcohols.md)
  - [7.2.7 Reactions of Alcohols](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-7-reactions-of-alcohols.md)
  - [7.2.8 Fermentation](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-8-fermentation.md)
  - [7.2.9 Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-9-carboxylic-acids.md)
  - [7.2.10 The Smallest Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-10-the-smallest-carboxylic-acids.md)
  - [7.2.11 Reactions of Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-11-reactions-of-carboxylic-acids.md)
  - [7.2.12 Addition Polymers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-12-addition-polymers.md)
  - [7.2.13 Addition Polymers Examples](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-13-addition-polymers-examples.md)
  - [7.2.14 Condensation Polymers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-14-condensation-polymers.md)
  - [7.2.15 Amino Acids](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-15-amino-acids.md)
  - [7.2.16 Naturally Occurring Polymers - Protein (Formation)](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-16-naturally-occurring-polymers-protein-formation.md)
  - [7.2.17 Naturally Occurring Polymers - Protein (Roles)](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-17-naturally-occurring-polymers-protein-roles.md)
  - [7.2.18 Naturally Occurring Polymers - DNA](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-18-naturally-occurring-polymers-dna.md)
  - [7.2.19 Naturally Occurring Polymers - Others](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-19-naturally-occurring-polymers-others.md)
  - [7.2.20 End of Topic Test - Alkanes & Alkenes](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-20-end-of-topic-test-alkanes-and-alkenes.md)
  - [7.2.21 End of Topic Test - Alcohols, Acids & Polymers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-21-end-of-topic-test-alcohols-acids-and-polymers.md)
  - [7.2.22 Grade 9 - Organic Chemistry](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-22-grade-9-organic-chemistry.md)
  - [7.2.23 Exam-Style Questions - Alcohols](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/7-2-23-exam-style-questions-alcohols.md)

### 8 Chemical Analysis
- 8.1 Purity, Formulations & Chromatography
  - [8.1.1 Purity](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-1-purity.md)
  - [8.1.2 Formulations](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-2-formulations.md)
  - [8.1.3 Chromatography](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-3-chromatography.md)
  - [8.1.4 Paper Chromatography 1](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-4-paper-chromatography-1.md)
  - [8.1.5 Paper Chromatography 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-5-paper-chromatography-2.md)
  - [8.1.6 Required Practical  - Paper Chromatography](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-6-required-practical-paper-chromatography.md)
  - [8.1.7 Diagnostic Misconceptions - Purity](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-1-7-diagnostic-misconceptions-purity.md)
- 8.2 Identification of Common Gases
  - [8.2.1 Identification of Hydrogen](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-2-1-identification-of-hydrogen.md)
  - [8.2.2 Identification of Oxygen](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-2-2-identification-of-oxygen.md)
  - [8.2.3 Identification of Carbon Dioxide](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-2-3-identification-of-carbon-dioxide.md)
  - [8.2.4 Identification of Chlorine](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-2-4-identification-of-chlorine.md)
- 8.3 Identifying Ions
  - [8.3.1 Flame Tests](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-1-flame-tests.md)
  - [8.3.2 Required Practical: Flame Tests](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-2-required-practical-flame-tests.md)
  - [8.3.3 Metal Hydroxides](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-3-metal-hydroxides.md)
  - [8.3.4 Metal Hydroxides 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-4-metal-hydroxides-2.md)
  - [8.3.5 Carbonates](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-5-carbonates.md)
  - [8.3.6 Halides](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-6-halides.md)
  - [8.3.7 Sulfates](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-7-sulfates.md)
  - [8.3.8 Methodology for Chemical Analysis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-8-methodology-for-chemical-analysis.md)
  - [8.3.9 Methodology for Chemical Analysis 2](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-9-methodology-for-chemical-analysis-2.md)
  - [8.3.10 Flame Emission Spectroscopy](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-10-flame-emission-spectroscopy.md)
  - [8.3.11 Flame Emission Spectroscopy Analysis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-11-flame-emission-spectroscopy-analysis.md)
  - [8.3.12 End of Topic Test - Chemical Analysis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-12-end-of-topic-test-chemical-analysis.md)
  - [8.3.13 Grade 9 - Chemical Analysis](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-13-grade-9-chemical-analysis.md)
  - [8.3.14 Exam-Style Questions - Identification of ions](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/8-3-14-exam-style-questions-identification-of-ions.md)

### 9 Chemistry of the Atmosphere
- 9.1 The Earth's Atmosphere
  - [9.1.1 Proportions of Gases in the Atmosphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-1-proportions-of-gases-in-the-atmosphere.md)
  - [9.1.2 The Earth's Early Atmosphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-2-the-earths-early-atmosphere.md)
  - [9.1.3 Oxygen in the Atmosphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-3-oxygen-in-the-atmosphere.md)
  - [9.1.4 Carbon Dioxide in the Atmosphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-4-carbon-dioxide-in-the-atmosphere.md)
  - [9.1.5 Greenhouse Gases](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-5-greenhouse-gases.md)
  - [9.1.6 Greenhouse Gases & Human Activities](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-6-greenhouse-gases-and-human-activities.md)
  - [9.1.7 Greenhouse Gases & Climate](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-7-greenhouse-gases-and-climate.md)
  - [9.1.8 Climate Change](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-8-climate-change.md)
  - [9.1.9 Carbon Footprints](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-9-carbon-footprints.md)
  - [9.1.10 Carbon Footprints Barriers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-10-carbon-footprints-barriers.md)
  - [9.1.11 Common Atmospheric Pollutants](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-11-common-atmospheric-pollutants.md)
  - [9.1.12 Properties of Atmospheric Pollutants](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-12-properties-of-atmospheric-pollutants.md)
  - [9.1.13 End of Topic Test - The Earth](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-13-end-of-topic-test-the-earth.md)
  - [9.1.14 Grade 9 - Chemistry of the Atmosphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-14-grade-9-chemistry-of-the-atmosphere.md)
  - [9.1.15 Exam-Style Questions - Earth's Atmosphere](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-15-exam-style-questions-earths-atmosphere.md)
  - [9.1.16 Diagnostic Misconceptions - Greenhouse Effect](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/9-1-16-diagnostic-misconceptions-greenhouse-effect.md)

### 10 Using Resources
- 10.1 Using the Earth's Resources
  - [10.1.1 Potable Water](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-1-potable-water.md)
  - [10.1.2 Potable Water Sources](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-2-potable-water-sources.md)
  - [10.1.3 Potable Water in the UK](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-3-potable-water-in-the-uk.md)
  - [10.1.4 Potable Water in Saudi Arabia](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-4-potable-water-in-saudi-arabia.md)
  - [10.1.5 Required Practical: Analysing and Purifying Water](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-5-required-practical-analysing-and-purifying-water.md)
  - [10.1.6 Natural Resources](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-6-natural-resources.md)
  - [10.1.7 Uses of Natural Resources](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-7-uses-of-natural-resources.md)
  - [10.1.8 Waste Water](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-8-waste-water.md)
  - [10.1.9 Sewage Treatment](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-9-sewage-treatment.md)
  - [10.1.10 Metal Ore Extraction](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-10-metal-ore-extraction.md)
  - [10.1.11 Properties of Copper](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-11-properties-of-copper.md)
  - [10.1.12 Overexploitation of Extraction Methods](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-12-overexploitation-of-extraction-methods.md)
  - [10.1.13 Alternative Extraction Methods](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-1-13-alternative-extraction-methods.md)
- 10.2 Life Cycle Assessments & Recycling
  - [10.2.1 Life Cycle Assessments](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-1-life-cycle-assessments.md)
  - [10.2.2 Comparative Life Cycle Assessments](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-2-comparative-life-cycle-assessments.md)
  - [10.2.3 Difficulties with LCA](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-3-difficulties-with-lca.md)
  - [10.2.4 Reducing Resource Usage](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-4-reducing-resource-usage.md)
  - [10.2.5 Reducing Use of Glass](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-5-reducing-use-of-glass.md)
  - [10.2.6 Reducing Use of Metal](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-6-reducing-use-of-metal.md)
  - [10.2.7 Exam-Style Questions - Life Cycle Assessments](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-2-7-exam-style-questions-life-cycle-assessments.md)
- 10.3 Using Materials
  - [10.3.1 Corrosion](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-3-1-corrosion.md)
  - [10.3.2 Preventing Corrosion](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-3-2-preventing-corrosion.md)
  - [10.3.3 Alloys](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-3-3-alloys.md)
  - [10.3.4 Ceramics](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-3-4-ceramics.md)
  - [10.3.5 Polymers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-3-5-polymers.md)
  - [10.3.6 Composites](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-3-6-composites.md)
- 10.4 The Haber Process & NPK Fertilisers
  - [10.4.1 Plants and Nitrogen](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-1-plants-and-nitrogen.md)
  - [10.4.2 The Haber Process](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-2-the-haber-process.md)
  - [10.4.3 The Haber Process - Equation](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-3-the-haber-process-equation.md)
  - [10.4.4 The Haber Process - Trade-Offs](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-4-the-haber-process-trade-offs.md)
  - [10.4.5 Importance of Fertilisers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-5-importance-of-fertilisers.md)
  - [10.4.6 Formulated vs Manure Fertilisers](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-6-formulated-vs-manure-fertilisers.md)
  - [10.4.7 NPK Fertilisers - N-containing Compound](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-7-npk-fertilisers-n-containing-compound.md)
  - [10.4.8 NPK Fertilisers - P-containing Compound](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-8-npk-fertilisers-p-containing-compound.md)
  - [10.4.9 NPK Fertilisers - K-containing Compound](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-9-npk-fertilisers-k-containing-compound.md)
  - [10.4.10 Nitrogen, Phosphorus and Potassium](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-10-nitrogen-phosphorus-and-potassium.md)
  - [10.4.11 End of Topic Test - Resources](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-11-end-of-topic-test-resources.md)
  - [10.4.12 Grade 9 - Using Resources](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-12-grade-9-using-resources.md)
  - [10.4.13 Exam-Style Questions - The Haber Process](https://senecalearning.com/en-gb/revision-notes/gcse/chemistry/aqa/higher/10-4-13-exam-style-questions-the-haber-process.md)
