IGCSE Chemistry 2026 - Study Guide Summary
IGCSE Chemistry 2026 Complete Study Guide - Key Points
Assessment Structure
- Paper 2: Multiple Choice, 45 min, 40 marks.
- Paper 4: Theory Extended, 75 min, 80 marks.
- Paper 6: Alternative to Practical, 60 min, 40 marks.
- Always verify with the official syllabus.
Topic Notes
01 States of Matter
- Three states: solid, liquid, gas.
- Properties vary (particle arrangement, movement, energy).
- Diffusion: movement from high to low concentration; gases diffuse faster than liquids.
- Brownian Motion: evidence for particle existence.
02 Atoms, Elements & Compounds
- Protons (Z), Neutrons (A-Z), Isotopes (same Z, different neutrons).
- Electronic Configuration: Shell max - 1: 2, 2: 8, 3: 8.
- Ions: Cations (positive) lose electrons, Anions (negative) gain electrons.
- 1 mole = 6.02 imes 10^{23} particles.
- Empirical vs Molecular Formulae: Simply ratios vs actual counts.
- Balancing Equations: Adjust coefficients, not subscripts.
04 Electrochemistry
- OILRIG: Oxidation Is Loss, Reduction Is Gain (electrons).
- Identifying ion discharge during electrolysis.
- Half-equations for reactions at electrodes.
05 Chemical Energetics
- Exothermic: release heat, negative ext{ΔH}. Endothermic: absorb heat, positive ext{ΔH}.
- Energy level diagrams illustrate energy changes in reactions.
06 Rates of Reaction & Equilibrium
- Rate changes with temperature, concentration, surface area, pressure.
- Le Chatelier's Principle: equilibrium shifts oppose external changes.
07 Acids, Bases & Salts
- Acids form H+ in solution; Bases produce OH-. Neutralization results in water.
- Distinction between strong and weak acids based on dissociation.
08 The Periodic Table
- Group 1: Alkali metals increase reactivity down the group.
- Group 7: Halogens decrease reactivity down the group.
- Transition metals have variable oxidation states.
- Reactivity series influences extraction methods: electrolysis vs reduction.
- Corrosion prevention techniques detailed; zinc as a sacrificial metal.
10 Chemistry of the Environment
- Air composition and common pollutants.
- Effect of pollutants on environmental issues (e.g., global warming, acid rain).
11 Organic Chemistry
- Homologous Series: general formulas for alkanes, alkenes, alcohols.
- Key reactions for organic compounds (combustion, addition, oxidation).
12 Experimental Techniques & Chemical Analysis
- Separation methods like filtration, distillation, chromatography.
- Ion and gas tests, Rf values in chromatography defined.
Exam Paper Tips
Paper 2 - Multiple Choice
- Use elimination and read questions carefully.
- Manage time effectively.
- Familiarize with flame tests and key topics beforehand.
Paper 4 - Theory Extended
- Mark allocation relates to answer length.
- Include units in calculations and precise vocabulary.
Paper 6 - Alternative to Practical
- Follow graphing and data recording guidelines.
- Identify anomalies and suggest improvements in experiments.
Frequently Asked Questions
- Clarifications on atomic structure, bonding types, catalyst functions, and processes like the Haber Process and Contact Process provided.