Source: https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-3-increasing-rates

[Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [A Level](https://senecalearning.com/en-gb/revision-notes/a-level.md) › [Chemistry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry.md) › [AQA](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa.md) › Increasing Rates

# Increasing Rates

Chemistry: AQA A Level, topic 1.5.3

## Changing Reaction Rates

There are many chemical reactions that we would like to go faster (e.g. the Haber process), and many that we would like to slow down (e.g. explosions). The main methods for changing reaction rates are:

### Changing temperature

![Changing temperature](https://image-v2.cdn.app.senecalearning.com/2018-08/3c5e14e6-2310-4bc7-a436-e2a9b4b176da/heating%20maxwell.png)

- Earlier, we saw the effect of heating on the Maxwell-Boltzmann distribution of energies.
 - It raises the average energy but lowers the peak of the graph.
- This gives more molecules energy greater than or equal to the activation energy.
 - This means more collisions will have the energy to react.
 - So the rate increases.
- Heating the mixture also increases the number of collisions.
 - So heating increases rate through two pathways.

### Changing concentration

![Changing concentration](https://image-v2.cdn.app.senecalearning.com/2018-08/6b796cf9-c8f3-4c49-95d9-6cbd62f7c4ca/2.2.1.1%20-%20The%20three%20states%20of%20matter%20depicted%20using%20the%20%E2%80%98simple%20sphere%E2%80%99%20model%20(1).png)

- In solution, the majority of collisions a solute particle experiences will be with water.
- We want more of these collisions to be with the other reactant, as then the rate will increase.
- By increasing the concentration of the solution, we increase the number of collisions that happen between reactants.
 - There will be more successful collisions.
 - The rate will increase.

### Changing pressure

![Changing pressure](https://image-v2.cdn.app.senecalearning.com/2018-08/6b796cf9-c8f3-4c49-95d9-6cbd62f7c4ca/2.2.1.1%20-%20The%20three%20states%20of%20matter%20depicted%20using%20the%20%E2%80%98simple%20sphere%E2%80%99%20model%20(1).png)

- In a gas, the molecules are far apart.
- Consider the ideal gas law: pV=nRT.
- Increasing pressure reduces the volume of the gas.
- This means the molecules are closer together.
- If the molecules are closer together, they will collide more often
 - Think of this as like being on a tube platform in rush hour; the closer everyone is, the more you bump into people.
- This means that there are more successful collisions
- The rate will increase.

### Catalysis

![Catalysis](https://image-v2.cdn.app.senecalearning.com/2018-08/d32c5e9b-0635-456f-a985-9885a4a455df/activation%20energies%20on%20maxwell%20catalytic.png)

- A catalyst helps to increase the reaction rate by offering an alternative reaction pathway.
 - The rate is higher because the new pathway has a lower activation energy.
- So a greater proportion of molecules will have energy greater than the activation energy. 
- So there will be more successful collisions.

## Diagrams to Explain Catalysis

Enthalpy profile diagrams and the Maxwell-Boltzmann Distribution can be used to explain how catalysts work.

### Enthalpy profile

![Enthalpy profile](https://image-v2.cdn.app.senecalearning.com/2018-08/5f5e818f-fd64-4335-a6e6-2c2227d6add6/Catalyst%20enthalpy%20profile.png)

- Here you can see both reaction pathways.
 - The catalytic pathway has a lower hump.
 - The hump represents the activation energy.
- So the catalytic pathway has a lower activation energy.

![](https://image-v2.cdn.app.senecalearning.com/2018-08/5f5e818f-fd64-4335-a6e6-2c2227d6add6/Catalyst%20enthalpy%20profile.png)

### Maxwell-Boltzmann graph

![Maxwell-Boltzmann graph](https://image-v2.cdn.app.senecalearning.com/2018-07/b3f0890d-4518-4c3d-af1b-965340bb0c15/activation%20energies%20on%20maxwell%20catalytic.jpg)

- Here you can see the different activation energies for each pathway.
 - Some molecules can use the old pathway.
 - Some molecules can use the new pathway but not the old pathway.
 - Some molecules can't use any.
- Overall, the catalytic pathway can be used by more molecules. 
 - More molecules have enough energy to react via the catalysed pathway.

### Maxwell-Boltzmann graph

![Maxwell-Boltzmann graph](https://image-v2.cdn.app.senecalearning.com/2018-07/b3f0890d-4518-4c3d-af1b-965340bb0c15/activation%20energies%20on%20maxwell%20catalytic.jpg)

## Test yourself on Increasing Rates

- In the Maxwell-Boltzmann distribution, where will the catalysed activation energy line lie relative to the uncatalysed activation energy line?
- Which is true for the catalysed reaction?
- Which of the following is NOT true for catalysed reactions?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/89dad2dd-9f68-460c-9247-131aea534bdb/section/df5d661b-6c61-40a0-9d9c-99aaff84d80f/session)

- Previous topic: [1.5.2 Maxwell-Boltzmann Distribution](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-2-maxwell-boltzmann-distribution.md)
- Next topic: [1.5.4 End of Topic Test - Kinetics](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-4-end-of-topic-test-kinetics.md)

## Chemistry: AQA A Level contents

### 1 Physical Chemistry
- 1.1 Atomic Structure
  - [1.1.1 Fundamental Particles](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-1-fundamental-particles.md)
  - [1.1.2 Isotopes & Mass Number](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-2-isotopes-and-mass-number.md)
  - [1.1.3 Mass Spectrometry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-3-mass-spectrometry.md)
  - [1.1.4 Electron Shells, Sub-Shells & Orbitals](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-4-electron-shells-sub-shells-and-orbitals.md)
  - [1.1.5 Electron Configuration](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-5-electron-configuration.md)
  - [1.1.6 Ionisation Energy](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-6-ionisation-energy.md)
  - [1.1.7 Factors Affecting Ionisation Energies](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-7-factors-affecting-ionisation-energies.md)
  - [1.1.8 Trends of Ionisation](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-8-trends-of-ionisation.md)
  - [1.1.9 Specific Impacts on Ionisation Energies](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-9-specific-impacts-on-ionisation-energies.md)
  - [1.1.10 End of Topic Test - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-10-end-of-topic-test-atomic-structure.md)
  - [1.1.11 A-A* (AO3/4) - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-1-11-a-a-ao34-atomic-structure.md)
- 1.2 Amount of Substance
  - [1.2.1 Relative Masses](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-1-relative-masses.md)
  - [1.2.2 The Mole](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-2-the-mole.md)
  - [1.2.3 The Ideal Gas Equation](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-3-the-ideal-gas-equation.md)
  - [1.2.4 Empirical & Molecular Formulae](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-4-empirical-and-molecular-formulae.md)
  - [1.2.5 Balanced Equations](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-5-balanced-equations.md)
  - [1.2.6 Percentage Yield](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-6-percentage-yield.md)
  - [1.2.7 A-A* (AO3/4) - Percentage Yield](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-7-a-a-ao34-percentage-yield.md)
  - [1.2.8 Atom Economy](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-8-atom-economy.md)
  - [1.2.9 End of Topic Test - Amount of Substance](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-9-end-of-topic-test-amount-of-substance.md)
  - [1.2.10 A-A* (AO3/4) - Substances & Yield](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-10-a-a-ao34-substances-and-yield.md)
  - [1.2.11 Diagnostic Misconceptions - Moles](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-2-11-diagnostic-misconceptions-moles.md)
- 1.3 Bonding
  - [1.3.1 Ionic Bonding](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-1-ionic-bonding.md)
  - [1.3.2 Covalent & Dative Bonding](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-2-covalent-and-dative-bonding.md)
  - [1.3.3 Carbon Structures](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-3-carbon-structures.md)
  - [1.3.4 Metallic Bonding](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-4-metallic-bonding.md)
  - [1.3.5 Physical Properties](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-5-physical-properties.md)
  - [1.3.6 Shapes of Molecules](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-6-shapes-of-molecules.md)
  - [1.3.7 Polarity](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-7-polarity.md)
  - [1.3.8 Intermolecular Forces](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-8-intermolecular-forces.md)
  - [1.3.9 Intermolecular Forces 2](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-9-intermolecular-forces-2.md)
  - [1.3.10 End of Topic Test - Bonding](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-10-end-of-topic-test-bonding.md)
  - [1.3.11 Exam-Style Question - Shape of Molecules](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-11-exam-style-question-shape-of-molecules.md)
  - [1.3.12 A-A* (AO3/4) - Bonding](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-12-a-a-ao34-bonding.md)
  - [1.3.13 Diagnostic Misconceptions - Ions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-13-diagnostic-misconceptions-ions.md)
  - [1.3.14 Diagnostic Misconceptions - Ionic & Covalent](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-14-diagnostic-misconceptions-ionic-and-covalent.md)
  - [1.3.15 Diagnostic Misconceptions - Phase Change](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-15-diagnostic-misconceptions-phase-change.md)
  - [1.3.16 Diagnostic Misconceptions - Boiling](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-16-diagnostic-misconceptions-boiling.md)
  - [1.3.17 Diagnostic Misconceptions - Polar Bonds](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-3-17-diagnostic-misconceptions-polar-bonds.md)
- 1.4 Energetics
  - [1.4.1 Enthalpy Changes](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-1-enthalpy-changes.md)
  - [1.4.2 Bond Breaking and Making](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-2-bond-breaking-and-making.md)
  - [1.4.3 Enthalpy Changes: Standard Conditions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-3-enthalpy-changes-standard-conditions.md)
  - [1.4.4 Calorimetry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-4-calorimetry.md)
  - [1.4.5 Hess' Law](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-5-hess-law.md)
  - [1.4.6 Bond Enthalpies](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-6-bond-enthalpies.md)
  - [1.4.7 End of Topic Test - Energetics](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-7-end-of-topic-test-energetics.md)
  - [1.4.8 Diagnostic Misconceptions - Calorimetry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-4-8-diagnostic-misconceptions-calorimetry.md)
- 1.5 Kinetics
  - [1.5.1 Collision Theory](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-1-collision-theory.md)
  - [1.5.2 Maxwell-Boltzmann Distribution](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-2-maxwell-boltzmann-distribution.md)
  - [1.5.3 Increasing Rates](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-3-increasing-rates.md)
  - [1.5.4 End of Topic Test - Kinetics](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-5-4-end-of-topic-test-kinetics.md)
- 1.6 Equilibria
  - [1.6.1 Le Chatelier](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-6-1-le-chatelier.md)
  - [1.6.2 Equilibrium Constants](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-6-2-equilibrium-constants.md)
  - [1.6.3 A-A* (AO3/4) - Energetics, Kinetics, Equilibria](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-6-3-a-a-ao34-energetics-kinetics-equilibria.md)
  - [1.6.4 End of Topic Test - Equilibria](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-6-4-end-of-topic-test-equilibria.md)
  - [1.6.5 Diagnostic Misconceptions - Solids](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-6-5-diagnostic-misconceptions-solids.md)
- 1.7 Redox
  - [1.7.1 Redox](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-7-1-redox.md)
  - [1.7.2 End of Topic Test - Redox](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/1-7-2-end-of-topic-test-redox.md)

### 2 Physical Chemistry 2 (A2 Only)
- 2.1 Thermodynamics (A2 Only)
  - [2.1.1 Born-Haber Cycles (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-1-1-born-haber-cycles-a2-only.md)
  - [2.1.2 Born-Haber Cycle Calculations (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-1-2-born-haber-cycle-calculations-a2-only.md)
  - [2.1.3 Entropy (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-1-3-entropy-a2-only.md)
  - [2.1.4 Free Energy (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-1-4-free-energy-a2-only.md)
  - [2.1.5 End of Topic Test - Thermodynamics](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-1-5-end-of-topic-test-thermodynamics.md)
  - [2.1.6 A-A* (AO3/4) - Thermodynamics](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-1-6-a-a-ao34-thermodynamics.md)
- 2.2 Rate Equations (A2 Only)
  - [2.2.1 Rate Equations (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-1-rate-equations-a2-only.md)
  - [2.2.2 Rate Equations 2 (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-2-rate-equations-2-a2-only.md)
  - [2.2.3 The Arrhenius Equation (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-3-the-arrhenius-equation-a2-only.md)
  - [2.2.4 Experimental Methods for Rates (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-4-experimental-methods-for-rates-a2-only.md)
  - [2.2.5 End of Topic Test - Rate Equations](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-5-end-of-topic-test-rate-equations.md)
  - [2.2.6 Exam-Style Question - Rates](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-6-exam-style-question-rates.md)
  - [2.2.7 A-A* (AO3/4) - Rate Equations](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-2-7-a-a-ao34-rate-equations.md)
- 2.3 The Equilibrium Constant Kp (A2 Only)
  - [2.3.1 Properties of Kp (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-3-1-properties-of-kp-a2-only.md)
- 2.4 Electrochemical Cells (A2 Only)
  - [2.4.1 Electrochemical Cells (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-1-electrochemical-cells-a2-only.md)
  - [2.4.2 Electrochemical Series (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-2-electrochemical-series-a2-only.md)
  - [2.4.3 Commercial Application (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-3-commercial-application-a2-only.md)
  - [2.4.4 End of Topic Test - Kp & Electrochemistry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-4-end-of-topic-test-kp-and-electrochemistry.md)
  - [2.4.5 A-A* (AO3/4) - Electrochemical Cells](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-5-a-a-ao34-electrochemical-cells.md)
  - [2.4.6 Diagnostic Misconceptions - Salt Bridges](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-6-diagnostic-misconceptions-salt-bridges.md)
  - [2.4.7 Diagnostic Misconceptions - Electrode, Electrolyte](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-4-7-diagnostic-misconceptions-electrode-electrolyte.md)
- 2.5 Acids & Bases (A2 Only)
  - [2.5.1 Brønsted-Lowry Acids & Bases (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-1-bronsted-lowry-acids-and-bases-a2-only.md)
  - [2.5.2 pH (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-2-ph-a2-only.md)
  - [2.5.3 The Ionic Product of Water (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-3-the-ionic-product-of-water-a2-only.md)
  - [2.5.4 Weak Acids & Bases (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-4-weak-acids-and-bases-a2-only.md)
  - [2.5.5 pH Curves & Titrations (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-5-ph-curves-and-titrations-a2-only.md)
  - [2.5.6 pH Curves & Titrations 2 (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-6-ph-curves-and-titrations-2-a2-only.md)
  - [2.5.7 Buffer Solutions (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-7-buffer-solutions-a2-only.md)
  - [2.5.8 End of Topic Test - Acids & Bases](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-8-end-of-topic-test-acids-and-bases.md)
  - [2.5.9 Exam-Style Question - Weak Acids](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-9-exam-style-question-weak-acids.md)
  - [2.5.10 A-A* (AO3/4) - Acids & Bases](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-10-a-a-ao34-acids-and-bases.md)
  - [2.5.11 Diagnostic Misconceptions - Ammonia is an Alkali](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-11-diagnostic-misconceptions-ammonia-is-an-alkali.md)
  - [2.5.12 Diagnostic Misconceptions - Water's Neutrality](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-12-diagnostic-misconceptions-waters-neutrality.md)
  - [2.5.13 Diagnostic Misconceptions - Concentrate & Strength](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/2-5-13-diagnostic-misconceptions-concentrate-and-strength.md)

### 3 Inorganic Chemistry
- 3.1 Periodicity & Trends
  - [3.1.1 The Periodic Table](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-1-1-the-periodic-table.md)
  - [3.1.2 Trends in the Periodic Table](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-1-2-trends-in-the-periodic-table.md)
  - [3.1.3 End of Topic Test - Periodicity & Trends](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-1-3-end-of-topic-test-periodicity-and-trends.md)
  - [3.1.4 Diagnostic Misconceptions - Atomic Radius](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-1-4-diagnostic-misconceptions-atomic-radius.md)
- 3.2 Group 2
  - [3.2.1 Group 2 Chemistry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-2-1-group-2-chemistry.md)
  - [3.2.2 End of Topic Test - Group 2](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-2-2-end-of-topic-test-group-2.md)
- 3.3 Group 7
  - [3.3.1 Introduction to Halogens](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-3-1-introduction-to-halogens.md)
  - [3.3.2 Reactions of Halogens](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-3-2-reactions-of-halogens.md)
  - [3.3.3 Chlorine & Chlorate(I)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-3-3-chlorine-and-chloratei.md)
  - [3.3.4 End of Topic Test - Group 7](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-3-4-end-of-topic-test-group-7.md)
  - [3.3.5 Exam-Style Question - Group 7](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-3-5-exam-style-question-group-7.md)
  - [3.3.6 A-A* (AO3/4) - Periodicity, Group 2 & 7](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/3-3-6-a-a-ao34-periodicity-group-2-and-7.md)

### 4 Inorganic Chemistry 2 (A2 Only)
- 4.1 Period 3 (A2 Only)
  - [4.1.1 Period 3 Elements & Oxides (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-1-1-period-3-elements-and-oxides-a2-only.md)
  - [4.1.2 Period 3 Oxides (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-1-2-period-3-oxides-a2-only.md)
  - [4.1.3 End of Topic Test - Period 3](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-1-3-end-of-topic-test-period-3.md)
- 4.2 Transition Metals (A2 Only)
  - [4.2.1 General Properties (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-1-general-properties-a2-only.md)
  - [4.2.2 Substitution Reactions (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-2-substitution-reactions-a2-only.md)
  - [4.2.3 Shapes of Complex Ions (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-3-shapes-of-complex-ions-a2-only.md)
  - [4.2.4 Colours of Ions (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-4-colours-of-ions-a2-only.md)
  - [4.2.5 Variable Oxidation States (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-5-variable-oxidation-states-a2-only.md)
  - [4.2.6 Titrations (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-6-titrations-a2-only.md)
  - [4.2.7 Homogeneous Catalysts (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-7-homogeneous-catalysts-a2-only.md)
  - [4.2.8 Heterogeneous Catalysts (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-8-heterogeneous-catalysts-a2-only.md)
  - [4.2.9 End of Topic Test - Transition Metals](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-9-end-of-topic-test-transition-metals.md)
  - [4.2.10 A-A* (AO3/4) - Transition Metals](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-2-10-a-a-ao34-transition-metals.md)
- 4.3 Reactions of Ions in Aqueous Solutions (A2 Only)
  - [4.3.1 Acidity (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-3-1-acidity-a2-only.md)
  - [4.3.2 Identification (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-3-2-identification-a2-only.md)
  - [4.3.3 End of Topic Test - Reactions of Ions in Solution](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/4-3-3-end-of-topic-test-reactions-of-ions-in-solution.md)

### 5 Organic Chemistry 1
- 5.1 Introduction
  - [5.1.1 Naming Conventions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-1-1-naming-conventions.md)
  - [5.1.2 Mechanism](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-1-2-mechanism.md)
  - [5.1.3 Isomerism](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-1-3-isomerism.md)
  - [5.1.4 End of Topic Test - Introduction to Organic Chem](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-1-4-end-of-topic-test-introduction-to-organic-chem.md)
- 5.2 Alkanes
  - [5.2.1 Fractional Distillation](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-2-1-fractional-distillation.md)
  - [5.2.2 Cracking](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-2-2-cracking.md)
  - [5.2.3 Combustion](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-2-3-combustion.md)
  - [5.2.4 Chlorination](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-2-4-chlorination.md)
  - [5.2.5 End of Topic Test - Alkanes](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-2-5-end-of-topic-test-alkanes.md)
- 5.3 Halogenoalkanes
  - [5.3.1 Substitution Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-3-1-substitution-reactions.md)
  - [5.3.2 Elimination Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-3-2-elimination-reactions.md)
  - [5.3.3 Ozone Depletion](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-3-3-ozone-depletion.md)
  - [5.3.4 End of Topic Test - Halogenoalkanes](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-3-4-end-of-topic-test-halogenoalkanes.md)
- 5.4 Alkenes
  - [5.4.1 Introduction to Alkenes](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-4-1-introduction-to-alkenes.md)
  - [5.4.2 Reactions of Alkenes](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-4-2-reactions-of-alkenes.md)
  - [5.4.3 Polymerisation Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-4-3-polymerisation-reactions.md)
  - [5.4.4 Properties of Polymers](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-4-4-properties-of-polymers.md)
  - [5.4.5 End of Topic Test - Alkenes](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-4-5-end-of-topic-test-alkenes.md)
- 5.5 Alcohols
  - [5.5.1 Production of Alcohols](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-5-1-production-of-alcohols.md)
  - [5.5.2 Oxidation of Alcohols](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-5-2-oxidation-of-alcohols.md)
  - [5.5.3 Oxidation of Alcohols - 2](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-5-3-oxidation-of-alcohols-2.md)
  - [5.5.4 Elimination Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-5-4-elimination-reactions.md)
  - [5.5.5 End of Topic Test - Alcohols](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-5-5-end-of-topic-test-alcohols.md)
  - [5.5.6 Exam-Style Question - Alcohols](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-5-6-exam-style-question-alcohols.md)
- 5.6 Organic Analysis
  - [5.6.1 Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-6-1-reactions.md)
  - [5.6.2 Reactions 2](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-6-2-reactions-2.md)
  - [5.6.3 Mass Spectrometry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-6-3-mass-spectrometry.md)
  - [5.6.4 Infrared Spectroscopy](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-6-4-infrared-spectroscopy.md)
  - [5.6.5 End of Topic Test - Organic Analysis](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-6-5-end-of-topic-test-organic-analysis.md)
- 5.7 A-A* (AO3/4) - Organic 1
  - [5.7.1 A-A* (AO3/4) - Organic 1](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/5-7-1-a-a-ao34-organic-1.md)

### 6 Organic Chemistry 2 (A2 Only)
- 6.1 Optical Isomerism (A2 Only)
  - [6.1.1 Optical Isomerism (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-1-1-optical-isomerism-a2-only.md)
  - [6.1.2 End of Topic Test - Optical Isomerism](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-1-2-end-of-topic-test-optical-isomerism.md)
- 6.2 Aldehydes & Ketones (A2 Only)
  - [6.2.1 Aldehydes & Ketones (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-2-1-aldehydes-and-ketones-a2-only.md)
  - [6.2.2 End of Topic Test - Aldehydes & Ketones](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-2-2-end-of-topic-test-aldehydes-and-ketones.md)
- 6.3 Carboxylic Acids & Esters (A2 Only)
  - [6.3.1 Acids & Esters (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-3-1-acids-and-esters-a2-only.md)
  - [6.3.2 Acylation (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-3-2-acylation-a2-only.md)
  - [6.3.3 End of Topic Test - Carboxylic Acids & Esters](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-3-3-end-of-topic-test-carboxylic-acids-and-esters.md)
- 6.4 Aromatic Chemistry (A2 Only)
  - [6.4.1 Structure & Reactivity (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-4-1-structure-and-reactivity-a2-only.md)
  - [6.4.2 Reactions of Benzene (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-4-2-reactions-of-benzene-a2-only.md)
  - [6.4.3 End of Topic Test - Aromatic Chemistry](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-4-3-end-of-topic-test-aromatic-chemistry.md)
- 6.5 Amines (A2 Only)
  - [6.5.1 Nature & Preparation of Amines (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-5-1-nature-and-preparation-of-amines-a2-only.md)
  - [6.5.2 Basicity & Nucleophilicity (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-5-2-basicity-and-nucleophilicity-a2-only.md)
  - [6.5.3 End of Topic Test - Amines](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-5-3-end-of-topic-test-amines.md)
- 6.6 Polymers (A2 Only)
  - [6.6.1 Condensation Polymers (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-6-1-condensation-polymers-a2-only.md)
  - [6.6.2 Biodegradability (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-6-2-biodegradability-a2-only.md)
- 6.7 Biological Organic (A2 Only)
  - [6.7.1 Amino Acids (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-7-1-amino-acids-a2-only.md)
  - [6.7.2 Proteins (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-7-2-proteins-a2-only.md)
  - [6.7.3 DNA (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-7-3-dna-a2-only.md)
  - [6.7.4 Anti-Cancer Drugs (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-7-4-anti-cancer-drugs-a2-only.md)
  - [6.7.5 End of Topic Test - Biological Organic](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-7-5-end-of-topic-test-biological-organic.md)
- 6.8 Organic Synthesis (A2 Only)
  - [6.8.1 Organic Synthesis (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-8-1-organic-synthesis-a2-only.md)
  - [6.8.2 Examples of Synthetic Routes (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-8-2-examples-of-synthetic-routes-a2-only.md)
  - [6.8.3 End of Topic Test - Polymers & Organic Synthesis](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-8-3-end-of-topic-test-polymers-and-organic-synthesis.md)
- 6.9 NMR Spectroscopy (A2 Only)
  - [6.9.1 Understanding NMR (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-9-1-understanding-nmr-a2-only.md)
  - [6.9.2 Carbon-13 NMR (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-9-2-carbon-13-nmr-a2-only.md)
  - [6.9.3 Hydrogen-1 NMR (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-9-3-hydrogen-1-nmr-a2-only.md)
  - [6.9.4 Hydrogen-1 NMR 2 (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-9-4-hydrogen-1-nmr-2-a2-only.md)
  - [6.9.5 End of Topic Test - NMR](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-9-5-end-of-topic-test-nmr.md)
- 6.10 Chromatography (A2 Only)
  - [6.10.1 Overview of Chromatography (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-10-1-overview-of-chromatography-a2-only.md)
  - [6.10.2 Thin-Layer Chromatography (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-10-2-thin-layer-chromatography-a2-only.md)
  - [6.10.3 Column Chromatography (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-10-3-column-chromatography-a2-only.md)
  - [6.10.4 Gas Chromatography (A2 Only)](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-10-4-gas-chromatography-a2-only.md)
  - [6.10.5 End of Topic Test - Chromatography](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-10-5-end-of-topic-test-chromatography.md)
- 6.11 A-A* (AO3/4) - Organic 2
  - [6.11.1 A-A* (AO3/4) - Organic 2](https://senecalearning.com/en-gb/revision-notes/a-level/chemistry/aqa/6-11-1-a-a-ao34-organic-2.md)