Source: https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-4-rate-determining-step

[Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [International A Level](https://senecalearning.com/en-gb/revision-notes/international-a-level.md) › [Chemistry](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry.md) › [Cambridge International](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international.md) › Rate Determining Step

# Rate Determining Step

Chemistry: Cambridge International A Level, topic 1.9.4

## The Rate Determining Step (RDS)

Reactions don’t always happen in one step. They may need many different collisions. Fortunately, most reactions have one step much slower than the rest, and so rate equations only depend on this one step.

### RDS

![RDS](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/2.2.1%20Thermal%20expansion/slow-tortoise-min.jpg)

- The rate determining step (RDS) is the slowest step in a reaction.
 - It is the slowest because it has the highest activation energy for a successful collision.

### An analogy for the RDS

![An analogy for the RDS](https://image-v2.cdn.app.senecalearning.com/2018-08/b31da3d9-60a7-422d-b155-9249cda806be/tube%20-%20station-%20barrier.png)

- You can think of it like the ticket barriers at a crowded tube station. 
 - People on the other side of the barriers can move very quickly, and people before the barriers can also move very quickly.
 - But it takes ages to get on a tube in rush hour because you can’t get through the barriers very fast.
 - Getting through the barriers is the rate determining step in your tube journey.

## Mechanistic Information

The rate equation for a reaction can give us some important details about the mechanism for the reaction.

### RDS and the reaction mechanism

![RDS and the reaction mechanism](https://image-v2.cdn.app.senecalearning.com/2018-08/995805af-6f23-4162-8636-68ed914acb39/brownian-motion-molecules-.jpg)

- Any reactant appearing in the rate equation is involved in the rate determining step (RDS).
- If two reactants appear in the rate equation, we know they’re both involved in the RDS.
 - This means the mechanism must involve them colliding at some point.

### Reactant orders

![Reactant orders](https://image-v2.cdn.app.senecalearning.com/2018-08/995805af-6f23-4162-8636-68ed914acb39/brownian-motion-molecules-.jpg)

- If a reactant appears in a rate equation, it will have an order.
 - If the order is one, then one molecule of the reactant is involved in the rate determining step.
 - If the order is two, then two molecules are involved.
- This gives us more information about which molecules, and how many of them, are colliding at some point in the mechanism.

### Reaction - nucleophile and halogenoalkane

![Reaction - nucleophile and halogenoalkane](https://image-v2.cdn.app.senecalearning.com/2018-08/995805af-6f23-4162-8636-68ed914acb39/brownian-motion-molecules-.jpg)

- There are two possible mechanisms for the reaction between a nucleophile (say, OH-) and a halogenoalkane (say, 2-bromo-2-methylbutane).
 - You can have a one-step process where the nucleophile collides with the halogenoalkane and ejects the bromide ion.
 - You could also have a two-step process where the bromide leaves first and then the nucleophile adds.
- For this reaction, it’s found that the rate equation is:
 - Rate = k[CH3CH2CH(CH3)BrCH3]
- This implies that the nucleophile is not involved in the RDS, and so the mechanism does not involve collision of the nucleophile with the halogenoalkane.

## Test yourself on Rate Determining Step

- What is a good analogy for the rate determining step (RDS)?
- What does RDS stand for?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/2eb3e96b-13a1-48db-b631-5d0098e3ed27/section/338b966f-bbf1-4e66-8a7f-d58a1bc9b299/session)

- Previous topic: [1.9.3 Rate Graphs](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-3-rate-graphs.md)
- Next topic: [1.9.5 Maxwell-Boltzmann Distribution](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-5-maxwell-boltzmann-distribution.md)

## Chemistry: Cambridge International A Level contents

### 1 Physical Chemistry
- 1.1 Atoms, Molecules & Stoichiometry
  - [1.1.1 Relative Masses](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-1-relative-masses.md)
  - [1.1.2 The Mole](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-2-the-mole.md)
  - [1.1.3 Mass Spectrometry](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-3-mass-spectrometry.md)
  - [1.1.4 Empirical & Molecular Formulae](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-4-empirical-and-molecular-formulae.md)
  - [1.1.5 Balanced Equations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-5-balanced-equations.md)
  - [1.1.6 Molar Volume](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-6-molar-volume.md)
  - [1.1.7 End of Topic Test - Amount of Substance](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-1-7-end-of-topic-test-amount-of-substance.md)
- 1.2 Atomic Structure
  - [1.2.1 Fundamental Particles](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-1-fundamental-particles.md)
  - [1.2.2 Isotopes & Mass Number](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-2-isotopes-and-mass-number.md)
  - [1.2.3 Electron Shells, Sub-Shells & Orbitals](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-3-electron-shells-sub-shells-and-orbitals.md)
  - [1.2.4 Electron Configuration](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-4-electron-configuration.md)
  - [1.2.5 Ionisation Energy](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-5-ionisation-energy.md)
  - [1.2.6 Factors Affecting Ionisation Energies](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-6-factors-affecting-ionisation-energies.md)
  - [1.2.7 Trends of Ionisation](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-7-trends-of-ionisation.md)
  - [1.2.8 Specific Impacts on Ionisation Energies](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-8-specific-impacts-on-ionisation-energies.md)
  - [1.2.9 Electron Affinity](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-9-electron-affinity.md)
  - [1.2.10 End of Topic Test - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-10-end-of-topic-test-atomic-structure.md)
  - [1.2.11 A-A* (AO2/3) - Atomic Structure](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-2-11-a-a-ao23-atomic-structure.md)
- 1.3 Chemical Bonding
  - [1.3.1 Ionic Bonding](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-1-ionic-bonding.md)
  - [1.3.2 Covalent & Dative Bonding](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-2-covalent-and-dative-bonding.md)
  - [1.3.3 Shapes of Molecules](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-3-shapes-of-molecules.md)
  - [1.3.4 Intermolecular Forces](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-4-intermolecular-forces.md)
  - [1.3.5 Intermolecular Forces 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-5-intermolecular-forces-2.md)
  - [1.3.6 Electronegativity](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-6-electronegativity.md)
  - [1.3.7 Bond Length, Bond Energy, & Bond Polarity](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-7-bond-length-bond-energy-and-bond-polarity.md)
  - [1.3.8 Metallic Bonding](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-8-metallic-bonding.md)
  - [1.3.9 Physical Properties](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-9-physical-properties.md)
  - [1.3.10 End of Topic Test - Bonding](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-10-end-of-topic-test-bonding.md)
  - [1.3.11 A-A* (AO2/3) - Bonding](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-3-11-a-a-ao23-bonding.md)
- 1.4 States of Matter
  - [1.4.1 Simple Covalent Molecules](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-1-simple-covalent-molecules.md)
  - [1.4.2 The Ideal Gas Equation](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-2-the-ideal-gas-equation.md)
  - [1.4.3 States of Matter](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-3-states-of-matter.md)
  - [1.4.4 Particle Diagrams](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-4-particle-diagrams.md)
  - [1.4.5 The Liquid State](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-5-the-liquid-state.md)
  - [1.4.6 Giant Ionic Lattices](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-6-giant-ionic-lattices.md)
  - [1.4.7 Giant Metallic Lattices](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-7-giant-metallic-lattices.md)
  - [1.4.8 Giant Covalent Structures](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-8-giant-covalent-structures.md)
  - [1.4.9 Graphene & Fullerene](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-9-graphene-and-fullerene.md)
  - [1.4.10 Recycling](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-4-10-recycling.md)
- 1.5 Chemical Energetics
  - [1.5.1 Calorimetry](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-1-calorimetry.md)
  - [1.5.2 Bond Enthalpies](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-2-bond-enthalpies.md)
  - [1.5.3 Enthalpy Changes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-3-enthalpy-changes.md)
  - [1.5.4 Hess' Law](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-4-hess-law.md)
  - [1.5.5 Born-Haber Cycles](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-5-born-haber-cycles.md)
  - [1.5.6 Born-Haber Cycle Calculations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-6-born-haber-cycle-calculations.md)
  - [1.5.7 Entropy](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-7-entropy.md)
  - [1.5.8 Free Energy](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-8-free-energy.md)
  - [1.5.9 End of Topic Test - Energetics](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-5-9-end-of-topic-test-energetics.md)
- 1.6 Electrochemistry
  - [1.6.1 Electrochemical Cells](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-6-1-electrochemical-cells.md)
  - [1.6.2 Electrochemical Series](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-6-2-electrochemical-series.md)
  - [1.6.3 Commercial Application](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-6-3-commercial-application.md)
  - [1.6.4 Nernst Equation](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-6-4-nernst-equation.md)
  - [1.6.5 Redox](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-6-5-redox.md)
- 1.7 Equilibria
  - [1.7.1 Dynamic Equilibrium & Le Chatelier](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-1-dynamic-equilibrium-and-le-chatelier.md)
  - [1.7.2 Kc](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-2-kc.md)
  - [1.7.3 Kp](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-3-kp.md)
  - [1.7.4 pH](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-4-ph.md)
  - [1.7.5 The Ionic Product of Water](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-5-the-ionic-product-of-water.md)
  - [1.7.6 Weak Acids & Bases](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-6-weak-acids-and-bases.md)
  - [1.7.7 Introduction to Solubility Equilibria](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-7-introduction-to-solubility-equilibria.md)
  - [1.7.8 Solubility Equilibria Calculations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-8-solubility-equilibria-calculations.md)
  - [1.7.9 Free Energy of Dissolution](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-9-free-energy-of-dissolution.md)
  - [1.7.10 pH and Solubility](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-10-ph-and-solubility.md)
  - [1.7.11 Common-Ion Effect](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-11-common-ion-effect.md)
  - [1.7.12 End of Topic Test - Kp & Electrochemistry](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-12-end-of-topic-test-kp-and-electrochemistry.md)
  - [1.7.13 A-A* (AO2/3) - Electrochemical Cells](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-7-13-a-a-ao23-electrochemical-cells.md)
- 1.8 Partition Coefficient
  - [1.8.1 Kpc](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-8-1-kpc.md)
- 1.9 Reaction Kinetics
  - [1.9.1 Collision Theory](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-1-collision-theory.md)
  - [1.9.2 Orders, Rate Constants & Equations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-2-orders-rate-constants-and-equations.md)
  - [1.9.3 Rate Graphs](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-3-rate-graphs.md)
  - [1.9.4 Rate Determining Step](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-4-rate-determining-step.md)
  - [1.9.5 Maxwell-Boltzmann Distribution](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-5-maxwell-boltzmann-distribution.md)
  - [1.9.6 Catalysts](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-6-catalysts.md)
  - [1.9.7 Homogeneous Catalysts](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-7-homogeneous-catalysts.md)
  - [1.9.8 Heterogeneous Catalysts](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-8-heterogeneous-catalysts.md)
  - [1.9.9 End of Topic Test - Kinetics](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-9-end-of-topic-test-kinetics.md)
  - [1.9.10 End of Topic Test - Rate Equations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-10-end-of-topic-test-rate-equations.md)
  - [1.9.11 A-A* (AO2/3) - Rate Equations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/1-9-11-a-a-ao23-rate-equations.md)

### 2 Inorganic Chemistry
- 2.1 The Periodic Table
  - [2.1.1 The Periodic Table](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-1-the-periodic-table.md)
  - [2.1.2 Trends in the Periodic Table](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-2-trends-in-the-periodic-table.md)
  - [2.1.3 End of Topic Test - Periodicity & Trends](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-3-end-of-topic-test-periodicity-and-trends.md)
  - [2.1.4 Ceramics](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-4-ceramics.md)
  - [2.1.5 Period 3 Elements & Oxides](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-5-period-3-elements-and-oxides.md)
  - [2.1.6 Period 3 Oxides](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-6-period-3-oxides.md)
  - [2.1.7 End of Topic Test - Period 3](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-1-7-end-of-topic-test-period-3.md)
- 2.2 Group 2
  - [2.2.1 Group 2 Chemistry](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-2-1-group-2-chemistry.md)
- 2.3 Group 17
  - [2.3.1 Introduction to Halogens](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-3-1-introduction-to-halogens.md)
  - [2.3.2 Reactions of Halogens](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-3-2-reactions-of-halogens.md)
  - [2.3.3 Chlorine & Chlorate(I)](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-3-3-chlorine-and-chloratei.md)
  - [2.3.4 End of Topic Test - Group 17](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-3-4-end-of-topic-test-group-17.md)
  - [2.3.5 A-A* (AO2/3) - Periodicity, Group 2 & 17](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-3-5-a-a-ao23-periodicity-group-2-and-17.md)
- 2.4 Transition Metals
  - [2.4.1 General Properties](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-1-general-properties.md)
  - [2.4.2 Titrations](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-2-titrations.md)
  - [2.4.3 Shapes of Complex Ions](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-3-shapes-of-complex-ions.md)
  - [2.4.4 Variable Oxidation States](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-4-variable-oxidation-states.md)
  - [2.4.5 Ligands](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-5-ligands.md)
  - [2.4.6 Colours of Ions](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-6-colours-of-ions.md)
  - [2.4.7 Stereoisomerism of Complex Ions](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-7-stereoisomerism-of-complex-ions.md)
  - [2.4.8 Cisplatin](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-8-cisplatin.md)
  - [2.4.9 Ligand Substitutions & Kstab](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-9-ligand-substitutions-and-kstab.md)
  - [2.4.10 End of Topic Test - Transition Metals](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-10-end-of-topic-test-transition-metals.md)
  - [2.4.11 A-A* (AO2/3) - Transition Metals](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-4-11-a-a-ao23-transition-metals.md)
- 2.5 Nitrogen & Sulfur
  - [2.5.1 Nitrogen & Ammonia](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-1-nitrogen-and-ammonia.md)
  - [2.5.2 Formulated vs Manure Fertilisers](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-2-formulated-vs-manure-fertilisers.md)
  - [2.5.3 Nitrogen Containing Fertilisers](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-3-nitrogen-containing-fertilisers.md)
  - [2.5.4 Fertilizers & Eutrophication](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-4-fertilizers-and-eutrophication.md)
  - [2.5.5 Common Atmospheric Pollutants & Their Properties](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-5-common-atmospheric-pollutants-and-their-properties.md)
  - [2.5.6 Catalytic Converters](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-6-catalytic-converters.md)
  - [2.5.7 Atmospheric Oxides](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/2-5-7-atmospheric-oxides.md)

### 3 Organic Chemistry & Analysis
- 3.1 Introduction to Organic Chemistry
  - [3.1.1 Naming Conventions](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-1-1-naming-conventions.md)
  - [3.1.2 Mechanism](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-1-2-mechanism.md)
  - [3.1.3 Isomerism](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-1-3-isomerism.md)
  - [3.1.4 End of Topic Test - Introduction to Organic Chem](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-1-4-end-of-topic-test-introduction-to-organic-chem.md)
- 3.2 Hydrocarbons
  - [3.2.1 Fractional Distillation](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-1-fractional-distillation.md)
  - [3.2.2 Cracking](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-2-cracking.md)
  - [3.2.3 Combustion](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-3-combustion.md)
  - [3.2.4 Chlorination](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-4-chlorination.md)
  - [3.2.5 End of Topic Test - Alkanes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-5-end-of-topic-test-alkanes.md)
  - [3.2.6 Introduction to Alkenes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-6-introduction-to-alkenes.md)
  - [3.2.7 Reactions of Alkenes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-7-reactions-of-alkenes.md)
  - [3.2.8 Polymerisation Reactions](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-8-polymerisation-reactions.md)
  - [3.2.9 End of Topic Test - Alkenes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-9-end-of-topic-test-alkenes.md)
  - [3.2.10 Arenes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-10-arenes.md)
  - [3.2.11 Evidence for Structure of Arenes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-11-evidence-for-structure-of-arenes.md)
  - [3.2.12 Reactions of Benzene](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-12-reactions-of-benzene.md)
  - [3.2.13 End of Topic Test -Arenes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-2-13-end-of-topic-test-arenes.md)
- 3.3 Halogen Derivatives
  - [3.3.1 Properties of Haloalkanes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-3-1-properties-of-haloalkanes.md)
  - [3.3.2 Substitution Reactions of Haloalkanes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-3-2-substitution-reactions-of-haloalkanes.md)
  - [3.3.3 Environmental Impacts of Haloalkanes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-3-3-environmental-impacts-of-haloalkanes.md)
  - [3.3.4 End of Topic Test - Halogenoalkanes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-3-4-end-of-topic-test-halogenoalkanes.md)
- 3.4 Hydroxy Compounds
  - [3.4.1 Types of Alcohol](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-1-types-of-alcohol.md)
  - [3.4.2 Oxidation 1](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-2-oxidation-1.md)
  - [3.4.3 Oxidation 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-3-oxidation-2.md)
  - [3.4.4 Elimination](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-4-elimination.md)
  - [3.4.5 Acids & Esters](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-5-acids-and-esters.md)
  - [3.4.6 Acyl Chlorides & Acylation](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-6-acyl-chlorides-and-acylation.md)
  - [3.4.7 Phenols & Their Reactions](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-7-phenols-and-their-reactions.md)
  - [3.4.8 End of Topic Test - Alcohols](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-4-8-end-of-topic-test-alcohols.md)
- 3.5 Carbonyl Compounds
  - [3.5.1 Carbonyls](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-5-1-carbonyls.md)
  - [3.5.2 Hydrogen Bonding & Carbonyls](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-5-2-hydrogen-bonding-and-carbonyls.md)
  - [3.5.3 Aldehydes & Ketones](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-5-3-aldehydes-and-ketones.md)
  - [3.5.4 Tri-Iodomethane Reaction](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-5-4-tri-iodomethane-reaction.md)
  - [3.5.5 End of Topic Test -Carbonyls](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-5-5-end-of-topic-test-carbonyls.md)
- 3.6 Carboxylic Acids & Derivatives
  - [3.6.1 Properties of Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-6-1-properties-of-carboxylic-acids.md)
  - [3.6.2 Esters](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-6-2-esters.md)
  - [3.6.3 Acyl Chlorides](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-6-3-acyl-chlorides.md)
  - [3.6.4 End of Topic Test - Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-6-4-end-of-topic-test-carboxylic-acids.md)
- 3.7 Nitrogen Compounds
  - [3.7.1 Nature & Preparation of Amines](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-7-1-nature-and-preparation-of-amines.md)
  - [3.7.2 Basicity & Nucleophilicity](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-7-2-basicity-and-nucleophilicity.md)
  - [3.7.3 Amides](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-7-3-amides.md)
  - [3.7.4 Reactions of Amino Acids](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-7-4-reactions-of-amino-acids.md)
  - [3.7.5 Amino Acids](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-7-5-amino-acids.md)
- 3.8 Polymerisation
  - [3.8.1 Properties of Addition Polymers](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-1-properties-of-addition-polymers.md)
  - [3.8.2 Condensation Polymerisation](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-2-condensation-polymerisation.md)
  - [3.8.3 Effects of Side-Chains on Polymers](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-3-effects-of-side-chains-on-polymers.md)
  - [3.8.4 Hydrolysis of Ester & Amide Groups](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-4-hydrolysis-of-ester-and-amide-groups.md)
  - [3.8.5 Proteins](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-5-proteins.md)
  - [3.8.6 DNA](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-6-dna.md)
  - [3.8.7 Adhesive & Conducting Polymers](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-7-adhesive-and-conducting-polymers.md)
  - [3.8.8 End of Topic Test - Amines & Proteins](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-8-8-end-of-topic-test-amines-and-proteins.md)
- 3.9 Analytical Techniques
  - [3.9.1 Chromatography](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-1-chromatography.md)
  - [3.9.2 High-Performance Liquid Chromatography](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-2-high-performance-liquid-chromatography.md)
  - [3.9.3 Gas Chromatography](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-3-gas-chromatography.md)
  - [3.9.4 IR Spectroscopy](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-4-ir-spectroscopy.md)
  - [3.9.5 Uses of IR Spectroscopy](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-5-uses-of-ir-spectroscopy.md)
  - [3.9.6 Mass Spectrometry](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-6-mass-spectrometry.md)
  - [3.9.7 Mass Spectrometry Analysis](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-7-mass-spectrometry-analysis.md)
  - [3.9.8 Nuclear Magnetic Resonance](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-8-nuclear-magnetic-resonance.md)
  - [3.9.9 Carbon-13 NMR](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-9-carbon-13-nmr.md)
  - [3.9.10 Proton NMR I](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-10-proton-nmr-i.md)
  - [3.9.11 Proton NMR II](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-11-proton-nmr-ii.md)
  - [3.9.12 End of Topic Test - Analytical Techniques](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-12-end-of-topic-test-analytical-techniques.md)
  - [3.9.13 A-A* (AO2/3) - Analytical Techniques](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-9-13-a-a-ao23-analytical-techniques.md)
- 3.10 Organic Synthesis
  - [3.10.1 Chirality & Drug Synthesis](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-10-1-chirality-and-drug-synthesis.md)
  - [3.10.2 Organic Synthesis](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-10-2-organic-synthesis.md)
  - [3.10.3 Examples of Synthetic Routes](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-10-3-examples-of-synthetic-routes.md)
  - [3.10.4 End of Topic Test - Organic Synthesis](https://senecalearning.com/en-gb/revision-notes/international-a-level/chemistry/cambridge-international/3-10-4-end-of-topic-test-organic-synthesis.md)
