Source: https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-2-balancing-symbols [Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [IGCSE](https://senecalearning.com/en-gb/revision-notes/igcse.md) › [Chemistry](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry.md) › [Edexcel IGCSE](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse.md) › [Higher](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher.md) › Balancing Symbols # Balancing Symbols Chemistry: Edexcel IGCSE, topic 5.1.2 ## Balancing Chemical Equations Chemical equations must be balanced to make sure that there are the same number of atoms of each element before and after a reaction. The reaction of hydrogen with oxygen to make water will be used as an example of how to do this: ### Unbalanced equation ![Unbalanced equation](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/3.1.1%20-%20Relative%20formula%20mass/UnbalancedLHS-min.jpg) - The unbalanced symbol equation for this reaction is: - H2 + O2 → H2O - The equation is unbalanced because there are 2 atoms of oxygen on the left hand side of the equation, but only 1 on the right hand side. ### Still unbalanced equation ![Still unbalanced equation](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/3.1.1%20-%20Relative%20formula%20mass/UnbalancedRHS-min.jpg) - We can increase the number of oxygen atoms on the right hand side by adding an H2O molecule: - H2 + O2 → 2H2O - However, the equation is still unbalanced as there are now more hydrogen atoms on the right hand side than on the left hand side. ### Balanced equation ![Balanced equation](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/1.1.1-Mixtures%20and%20compounds/Balancing%20equations-min.jpg) - The final step is to add an H2 molecule to the left hand side: - 2H2 + O2 → 2H2O - Our equation is now balanced. ## Test yourself on Balancing Symbols - H2 + O2 → 2H2O Why is this equation unbalanced? - Select the true statement in each pair. - In the process of balancing chemical equations, why is it important to have the same number of atoms of each element on both sides of the equation? - Which step in balancing the chemical equation for the reaction of hydrogen with oxygen to make water ensures that there are the same number of oxygen atoms on both sides of the equation? - What is the balanced symbol equation for the reaction of hydrogen with oxygen to make water? [Practise this topic for free](https://app.senecalearning.com/classroom/course/967b4370-21e8-11e8-8c0c-d79041e9c8a6/section/568f61c5-88c4-43ff-b6d5-152ca2918317/session) - Previous topic: [5.1.1 Forming Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-1-forming-equations.md) - Next topic: [5.1.3 State Symbols](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-3-state-symbols.md) ## Chemistry: Edexcel IGCSE contents ### 1 States of Matter - 1.1 States of Matter - [1.1.1 States of Matter](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-1-states-of-matter.md) - [1.1.2 Simple Sphere](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-2-simple-sphere.md) - [1.1.3 Changes of State](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-3-changes-of-state.md) - [1.1.4 Changes of State 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-4-changes-of-state-2.md) - [1.1.5 Changes of State 3](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-5-changes-of-state-3.md) - [1.1.6 Changes of State and Temperature](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-6-changes-of-state-and-temperature.md) - [1.1.7 Solubility](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-7-solubility.md) - [1.1.8 Solubility Curves](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-8-solubility-curves.md) - [1.1.9 Solubility - Experiments](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-9-solubility-experiments.md) - [1.1.10 Diffusion - Experiment](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-10-diffusion-experiment.md) - [1.1.11 Changing State HyperLearning](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/1-1-11-changing-state-hyperlearning.md) ### 2 Elements, Compounds & Mixtures - 2.1 Elements, Mixtures & Compounds - [2.1.1 Elements & Compounds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-1-elements-and-compounds.md) - [2.1.2 Chemical Formula](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-2-chemical-formula.md) - [2.1.3 Mixtures](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-3-mixtures.md) - [2.1.4 Purity](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-4-purity.md) - [2.1.5 Separating Mixtures](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-5-separating-mixtures.md) - [2.1.6 Separating Mixtures 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-6-separating-mixtures-2.md) - [2.1.7 Paper Chromatography](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-7-paper-chromatography.md) - [2.1.8 Paper Chromatography Analysis](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-8-paper-chromatography-analysis.md) - [2.1.9 Paper Chromatography - Practical](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-9-paper-chromatography-practical.md) - [2.1.10 End of Topic Test - Elements,Compounds,Mixtures](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-10-end-of-topic-test-elementscompoundsmixtures.md) - [2.1.11 Grade 9 - Chromatography](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-11-grade-9-chromatography.md) - [2.1.12 Exam-Style Questions - Separation of Mixtures](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/2-1-12-exam-style-questions-separation-of-mixtures.md) ### 3 Atomic Structure - 3.1 Atoms - [3.1.1 Atomic Structure](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-1-atomic-structure.md) - [3.1.2 Atom Size](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-2-atom-size.md) - [3.1.3 Subatomic Particles](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-3-subatomic-particles.md) - [3.1.4 Atomic Number](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-4-atomic-number.md) - [3.1.5 Relative Atomic Mass](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-5-relative-atomic-mass.md) - [3.1.6 Isotopes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-6-isotopes.md) - [3.1.7 Isotopes 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/3-1-7-isotopes-2.md) ### 4 The Periodic Table - 4.1 The Periodic Table - [4.1.1 Periodic Table Arrangement](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-1-periodic-table-arrangement.md) - [4.1.2 Electron Structure](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-2-electron-structure.md) - [4.1.3 Metals & Non-Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-3-metals-and-non-metals.md) - [4.1.4 Noble Gases](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-4-noble-gases.md) - [4.1.5 End of Topic Test- Atomic Structure,Periodic Table](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-5-end-of-topic-test-atomic-structureperiodic-table.md) - [4.1.6 Grade 9 - Atomic Structure, Periodic Table](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-6-grade-9-atomic-structure-periodic-table.md) - [4.1.7 Exam-Style Questions -Alkali Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/4-1-7-exam-style-questions-alkali-metals.md) ### 5 Chemical Formulae, Equations & Calculations - 5.1 Equations - [5.1.1 Forming Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-1-forming-equations.md) - [5.1.2 Balancing Symbols](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-2-balancing-symbols.md) - [5.1.3 State Symbols](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-3-state-symbols.md) - [5.1.4 Relative Formula Mass](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-4-relative-formula-mass.md) - [5.1.5 Calculating Relative Formula Mass](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-5-calculating-relative-formula-mass.md) - [5.1.6 Relative Formula Mass - Calculations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-6-relative-formula-mass-calculations.md) - [5.1.7 Introducing Moles](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-7-introducing-moles.md) - [5.1.8 Relative Formula Mass](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-8-relative-formula-mass.md) - [5.1.9 Amounts of Substance](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-9-amounts-of-substance.md) - [5.1.10 Moles & Yield](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-10-moles-and-yield.md) - [5.1.11 Moles - Calculations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-11-moles-calculations.md) - [5.1.12 Balancing Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-12-balancing-equations.md) - [5.1.13 Moles to Balance Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-13-moles-to-balance-equations.md) - [5.1.14 Limiting Reactants](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-14-limiting-reactants.md) - [5.1.15 Chemical Measurements](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-15-chemical-measurements.md) - [5.1.16 Calculating Mass](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-16-calculating-mass.md) - [5.1.17 Changing Mass](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-17-changing-mass.md) - [5.1.18 Exam-Style Questions - Moles](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-18-exam-style-questions-moles.md) - [5.1.19 Percentage Yield](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-19-percentage-yield.md) - [5.1.20 Calculating Yield](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-20-calculating-yield.md) - [5.1.21 Percentage Yield - Calculations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-21-percentage-yield-calculations.md) - [5.1.22 Empirical & Molecular Formula](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-22-empirical-and-molecular-formula.md) - [5.1.23 Experiment for Empirical Formula](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-23-experiment-for-empirical-formula.md) - [5.1.24 Empirical Formula - Calculations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-24-empirical-formula-calculations.md) - [5.1.25 Concentrations & Amounts](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-25-concentrations-and-amounts.md) - [5.1.26 Conclusion of Solutions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-26-conclusion-of-solutions.md) - [5.1.27 Volumes and Gases](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-27-volumes-and-gases.md) - [5.1.28 Concentration & Amounts - Calculations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-28-concentration-and-amounts-calculations.md) - [5.1.29 End of Topic Test - Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-29-end-of-topic-test-equations.md) - [5.1.30 Grade 9 - Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/5-1-30-grade-9-equations.md) ### 6 Bonding - 6.1 Ionic Bonding - [6.1.1 Dot & Cross Diagrams](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-1-dot-and-cross-diagrams.md) - [6.1.2 Changes in Number of Subatomic Particles](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-2-changes-in-number-of-subatomic-particles.md) - [6.1.3 Ionic Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-3-ionic-bonding.md) - [6.1.4 Ions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-4-ions.md) - [6.1.5 Types of Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-5-types-of-bonding.md) - [6.1.6 Ion Formation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-6-ion-formation.md) - [6.1.7 Identifying Ionic Compounds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-7-identifying-ionic-compounds.md) - [6.1.8 Ionic Compounds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-8-ionic-compounds.md) - [6.1.9 Ionic and Metallic Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-9-ionic-and-metallic-bonding.md) - [6.1.10 Ion Charges](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-1-10-ion-charges.md) - 6.2 Covalent Bonding - [6.2.1 Covalent Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-1-covalent-bonding.md) - [6.2.2 Dot-and-Cross Diagrams](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-2-dot-and-cross-diagrams.md) - [6.2.3 Representing Covalent Bonds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-3-representing-covalent-bonds.md) - [6.2.4 Covalent Bond Examples](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-4-covalent-bond-examples.md) - [6.2.5 Covalent Bond Examples 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-5-covalent-bond-examples-2.md) - [6.2.6 Simple Covalent Molecules](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-6-simple-covalent-molecules.md) - [6.2.7 Chemical Properties of Small Molecules](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-7-chemical-properties-of-small-molecules.md) - [6.2.8 Giant Covalent Structures](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-8-giant-covalent-structures.md) - [6.2.9 Giant Covalent Structures 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-9-giant-covalent-structures-2.md) - [6.2.10 Carbon Structures - Diamonds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-10-carbon-structures-diamonds.md) - [6.2.11 Carbon Structures - Graphite](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-11-carbon-structures-graphite.md) - [6.2.12 Carbon Structures - Fullerenes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-12-carbon-structures-fullerenes.md) - [6.2.13 Carbon Structures - Summary](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-13-carbon-structures-summary.md) - [6.2.14 Exam-Style Questions - Allotropes of Carbon](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-2-14-exam-style-questions-allotropes-of-carbon.md) - 6.3 Metallic Bonding - [6.3.1 Metallic Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-3-1-metallic-bonding.md) - [6.3.2 Metals as Conductors](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-3-2-metals-as-conductors.md) - [6.3.3 Pure Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-3-3-pure-metals.md) - [6.3.4 End of Topic Test - Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-3-4-end-of-topic-test-bonding.md) - [6.3.5 Grade 9 - Bonding](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-3-5-grade-9-bonding.md) - [6.3.6 Exam-Style Questions - Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/6-3-6-exam-style-questions-metals.md) ### 7 Electrolysis - 7.1 Electrolysis - [7.1.1 Molten Ionic Compounds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-1-molten-ionic-compounds.md) - [7.1.2 Electrolysis - Process](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-2-electrolysis-process.md) - [7.1.3 Electrolysis - Aqueous Solutions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-3-electrolysis-aqueous-solutions.md) - [7.1.4 Electrolysis - Copper Sulfate](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-4-electrolysis-copper-sulfate.md) - [7.1.5 Electrolysis - Examples](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-5-electrolysis-examples.md) - [7.1.6 Half Equations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-6-half-equations.md) - [7.1.7 Exam-Style Questions - Electrolysis](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/7-1-7-exam-style-questions-electrolysis.md) ### 8 Groups of the Periodic Table - 8.1 Alkali Metals & Halogens - [8.1.1 Alkali Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-1-alkali-metals.md) - [8.1.2 Alkali Metals - Properties](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-2-alkali-metals-properties.md) - [8.1.3 Alkali Metal Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-3-alkali-metal-reactions.md) - [8.1.4 Reactivity of Alkali Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-4-reactivity-of-alkali-metals.md) - [8.1.5 Halogens - Properties](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-5-halogens-properties.md) - [8.1.6 Halogens - Colours and States](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-6-halogens-colours-and-states.md) - [8.1.7 Halogen - Displacement Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-7-halogen-displacement-reactions.md) - [8.1.8 Halogen - Displacement Reactions 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-8-halogen-displacement-reactions-2.md) - [8.1.9 Reactions Between Halogens and Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-9-reactions-between-halogens-and-metals.md) - [8.1.10 Hydrogen Halides](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-10-hydrogen-halides.md) - [8.1.11 End of Topic Test - Alkali Metals & Halogens](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-11-end-of-topic-test-alkali-metals-and-halogens.md) - [8.1.12 Grade 9 - Alkali Metals & Halogens](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-12-grade-9-alkali-metals-and-halogens.md) - [8.1.13 Exam-Style Questions - Alkali Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/8-1-13-exam-style-questions-alkali-metals.md) ### 9 The Atmosphere - 9.1 Gases in the Atmosphere - [9.1.1 Gases in the Air](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-1-gases-in-the-air.md) - [9.1.2 Calculating Oxygen in the Air - Metal](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-2-calculating-oxygen-in-the-air-metal.md) - [9.1.3 Calculating Oxygen in the Air - Non-Metal](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-3-calculating-oxygen-in-the-air-non-metal.md) - [9.1.4 Oxygen](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-4-oxygen.md) - [9.1.5 Carbon Dioxide](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-5-carbon-dioxide.md) - [9.1.6 Greenhouse Gases](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-6-greenhouse-gases.md) - [9.1.7 Greenhouse Gases & Human Activities](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-7-greenhouse-gases-and-human-activities.md) - [9.1.8 Greenhouse Gases & Climate](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-8-greenhouse-gases-and-climate.md) - [9.1.9 End of Topic Test - Gases in the Atmosphere](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-9-end-of-topic-test-gases-in-the-atmosphere.md) - [9.1.10 Grade 9 - Gases in the Atmosphere](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/9-1-10-grade-9-gases-in-the-atmosphere.md) ### 10 Reactivity Series - 10.1 Reactivity Series - [10.1.1 Reactivity Diagram](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-1-reactivity-diagram.md) - [10.1.2 Displacement Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-2-displacement-reactions.md) - [10.1.3 Reactivity Tests - Water](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-3-reactivity-tests-water.md) - [10.1.4 Reactivity Tests - Acid](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-4-reactivity-tests-acid.md) - [10.1.5 Reactivity Tests - Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-5-reactivity-tests-metals.md) - [10.1.6 Corrosion](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-6-corrosion.md) - [10.1.7 Preventing Corrosion](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-7-preventing-corrosion.md) - [10.1.8 Metal Oxide](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-8-metal-oxide.md) - [10.1.9 Oxidisation & Reduction](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-9-oxidisation-and-reduction.md) - [10.1.10 Redox Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-10-redox-reactions.md) - [10.1.11 End of Topic Test - Reactivity Series](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-11-end-of-topic-test-reactivity-series.md) - [10.1.12 Grade 9 - Reactivity Series](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-12-grade-9-reactivity-series.md) - [10.1.13 Exam-Style Questions - Redox Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/10-1-13-exam-style-questions-redox-reactions.md) ### 11 Metal Extraction - 11.1 Metal Extraction - [11.1.1 Extracting Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/11-1-1-extracting-metals.md) - [11.1.2 Extracting Metals - Electrolysis](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/11-1-2-extracting-metals-electrolysis.md) - [11.1.3 Alloys](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/11-1-3-alloys.md) - [11.1.4 Metal Alloys](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/11-1-4-metal-alloys.md) - [11.1.5 End of Topic Test - Extracting Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/11-1-5-end-of-topic-test-extracting-metals.md) - [11.1.6 Grade 9 - Extracting Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/11-1-6-grade-9-extracting-metals.md) ### 12 Acids & Alkalis - 12.1 Acids, Alkalis & Titrations - [12.1.1 Acids and Alkali Indicators](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-1-acids-and-alkali-indicators.md) - [12.1.2 Is it an Acid or Alkali?](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-2-is-it-an-acid-or-alkali.md) - [12.1.3 The pH Scale](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-3-the-ph-scale.md) - [12.1.4 Titrations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-4-titrations.md) - [12.1.5 Titration - Practical](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-5-titration-practical.md) - [12.1.6 Titrations - Methods](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-6-titrations-methods.md) - [12.1.7 Soluble Salts](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-7-soluble-salts.md) - [12.1.8 Solubility of Salts](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-8-solubility-of-salts.md) - [12.1.9 Making Insoluble Salts](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-9-making-insoluble-salts.md) - [12.1.10 Required Practical: Separating Mixtures](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-10-required-practical-separating-mixtures.md) - [12.1.11 Reaction of Acid & Metals](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-11-reaction-of-acid-and-metals.md) - [12.1.12 Neutralisation of Acids](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-12-neutralisation-of-acids.md) - [12.1.13 Strong vs Weak Bases](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-13-strong-vs-weak-bases.md) - [12.1.14 End of Topic Test - Acids & Alkalis](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-14-end-of-topic-test-acids-and-alkalis.md) - [12.1.15 Grade 9 - Acids & Alkalis](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-15-grade-9-acids-and-alkalis.md) - [12.1.16 Exam-Style Questions - Neutralisation & Titrations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/12-1-16-exam-style-questions-neutralisation-and-titrations.md) ### 13 Chemical Tests - 13.1 Identifying Gases - [13.1.1 Hydrogen](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-1-1-hydrogen.md) - [13.1.2 Oxygen](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-1-2-oxygen.md) - [13.1.3 Carbon Dioxide](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-1-3-carbon-dioxide.md) - [13.1.4 Chlorine](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-1-4-chlorine.md) - [13.1.5 Ammonia](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-1-5-ammonia.md) - 13.2 Testing Anions, Cations & Water - [13.2.1 Flame Tests](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-1-flame-tests.md) - [13.2.2 Flame Test - Practical](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-2-flame-test-practical.md) - [13.2.3 Metal Hydroxides](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-3-metal-hydroxides.md) - [13.2.4 Testing Cations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-4-testing-cations.md) - [13.2.5 Testing for Aqueous Cations](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-5-testing-for-aqueous-cations.md) - [13.2.6 Testing Carbonates](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-6-testing-carbonates.md) - [13.2.7 Testing Halides](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-7-testing-halides.md) - [13.2.8 Testing for Carbonate and Halides](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-8-testing-for-carbonate-and-halides.md) - [13.2.9 Testing Sulfates](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-9-testing-sulfates.md) - [13.2.10 Testing Sulfates 2](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-10-testing-sulfates-2.md) - [13.2.11 Testing Water](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-11-testing-water.md) - [13.2.12 Testing Water Purity](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-12-testing-water-purity.md) - [13.2.13 End of Topic Test - Chemical Tests](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-13-end-of-topic-test-chemical-tests.md) - [13.2.14 Grade 9 - Chemical Tests](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-14-grade-9-chemical-tests.md) - [13.2.15 Exam-Style Questions - Identifying Gases & Ions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/13-2-15-exam-style-questions-identifying-gases-and-ions.md) ### 14 Physical Chemistry - 14.1 Energetics - [14.1.1 Energy Conservation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-1-energy-conservation.md) - [14.1.2 Exothermic Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-2-exothermic-reactions.md) - [14.1.3 Endothermic Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-3-endothermic-reactions.md) - [14.1.4 Heat Changes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-4-heat-changes.md) - [14.1.5 Calculating Heat Energy Transferred](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-5-calculating-heat-energy-transferred.md) - [14.1.6 Molar Enthalpy Change](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-6-molar-enthalpy-change.md) - [14.1.7 Reaction Profiles](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-7-reaction-profiles.md) - [14.1.8 Reaction Profiles - Catalysed vs Uncatalysed](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-8-reaction-profiles-catalysed-vs-uncatalysed.md) - [14.1.9 Exam-Style Questions - Reaction Profiles](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-9-exam-style-questions-reaction-profiles.md) - [14.1.10 Chemical Bonds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-10-chemical-bonds.md) - [14.1.11 Bond Energies](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-1-11-bond-energies.md) - 14.2 Rates of Reaction - [14.2.1 Reaction Practicals - Measuring Gas Production](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-1-reaction-practicals-measuring-gas-production.md) - [14.2.2 Reaction Practicals - Observing a Colour Change](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-2-reaction-practicals-observing-a-colour-change.md) - [14.2.3 Rate of Reaction - Collision Theory](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-3-rate-of-reaction-collision-theory.md) - [14.2.4 Rate of Reaction - Key Factors](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-4-rate-of-reaction-key-factors.md) - [14.2.5 Rate of Reaction - Catalysts](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-5-rate-of-reaction-catalysts.md) - [14.2.6 End of Topic Test - Energetics & Rates](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-6-end-of-topic-test-energetics-and-rates.md) - [14.2.7 Grade 9 - Energetics & Rates](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-2-7-grade-9-energetics-and-rates.md) - 14.3 Reversible Reactions & Equilibria - [14.3.1 Reversible Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-3-1-reversible-reactions.md) - [14.3.2 Dynamic Equilibrium](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-3-2-dynamic-equilibrium.md) - [14.3.3 Conditions and Equilibrium](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-3-3-conditions-and-equilibrium.md) - [14.3.4 Equilibrium Position - Temperature](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-3-4-equilibrium-position-temperature.md) - [14.3.5 Equilibrium Position - Pressure](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-3-5-equilibrium-position-pressure.md) - [14.3.6 End of Topic Test - Equilibria](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/14-3-6-end-of-topic-test-equilibria.md) ### 15 Organic Chemistry - 15.1 Hydrocarbons - [15.1.1 Crude Oil](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-1-crude-oil.md) - [15.1.2 Properties of Hydrocarbons](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-2-properties-of-hydrocarbons.md) - [15.1.3 Fractional Distillation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-3-fractional-distillation.md) - [15.1.4 Process of Fractional Distillation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-4-process-of-fractional-distillation.md) - [15.1.5 Fractions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-5-fractions.md) - [15.1.6 Combustion of Hydrocarbons](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-6-combustion-of-hydrocarbons.md) - [15.1.7 Impurities](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-7-impurities.md) - [15.1.8 Heavy Fractions of Crude Oil](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-8-heavy-fractions-of-crude-oil.md) - [15.1.9 Cracking](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-1-9-cracking.md) - 15.2 Alkanes & Alkenes - [15.2.1 Homologous Series](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-1-homologous-series.md) - [15.2.2 Alkanes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-2-alkanes.md) - [15.2.3 Smallest Alkanes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-3-smallest-alkanes.md) - [15.2.4 Structural Isomerism](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-4-structural-isomerism.md) - [15.2.5 Structure of Alkenes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-5-structure-of-alkenes.md) - [15.2.6 The Shortest Alkenes](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-6-the-shortest-alkenes.md) - [15.2.7 Alkene Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-7-alkene-reactions.md) - [15.2.8 Types of Alkene Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-8-types-of-alkene-reactions.md) - [15.2.9 Q5 - Alkene Reactions](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-2-9-q5-alkene-reactions.md) - 15.3 Alcohols - [15.3.1 Alcohols](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-1-alcohols.md) - [15.3.2 Smallest Alcohols](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-2-smallest-alcohols.md) - [15.3.3 Combustion of Alcohols](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-3-combustion-of-alcohols.md) - [15.3.4 Oxidisation of Ethanol](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-4-oxidisation-of-ethanol.md) - [15.3.5 Fermentation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-5-fermentation.md) - [15.3.6 Ethanol Hydration](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-6-ethanol-hydration.md) - [15.3.7 Fermentation vs Hydration of Ethene](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-3-7-fermentation-vs-hydration-of-ethene.md) - 15.4 Carboxylic Acids - [15.4.1 Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-4-1-carboxylic-acids.md) - [15.4.2 Smallest Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-4-2-smallest-carboxylic-acids.md) - [15.4.3 Reactions of Carboxylic Acids](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-4-3-reactions-of-carboxylic-acids.md) - 15.5 Esters - [15.5.1 Esters](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-5-1-esters.md) - [15.5.2 Ethyl Ethanoate](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-5-2-ethyl-ethanoate.md) - 15.6 Synthetic Polymers - [15.6.1 Polymers](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-6-1-polymers.md) - [15.6.2 Addition Polymerisation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-6-2-addition-polymerisation.md) - [15.6.3 Examples of Addition Polymerisation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-6-3-examples-of-addition-polymerisation.md) - [15.6.4 Problems With Polymers](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-6-4-problems-with-polymers.md) - [15.6.5 Condensation Polymerisation](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-6-5-condensation-polymerisation.md) - 15.7 End of Topic - Organic Chemistry - [15.7.1 End of Topic Test - Organic Chemistry](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-7-1-end-of-topic-test-organic-chemistry.md) - [15.7.2 Grade 9 - Organic Chemistry](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-7-2-grade-9-organic-chemistry.md) - [15.7.3 Exam-Style Questions - Organic Compounds](https://senecalearning.com/en-gb/revision-notes/igcse/chemistry/edexcel-igcse/higher/15-7-3-exam-style-questions-organic-compounds.md)