Skip to content
Chemistry notebook Cambridge IGCSE 0620

Topic 6 of 12 · 4 modules planned

Chemical reactions

What counts as a chemical change, how fast it happens, when it reverses and how electrons move.

Modules

  1. Module 1 · syllabus 6.1

    Physical and chemical changes

    Did a new substance form?

    This module is planned. It will have readings, an experiment, practice with self-checks and a final check.

Syllabus statements for this topic · for teachers · 33 statements

Core for every pupil · Supplement also for Extended entry. Paraphrased from the Cambridge IGCSE Chemistry 0620 syllabus (2026–2028); check the official syllabus for exact wording.

6.1 Physical and chemical changes

  • 6.1.1Substance identity in physical/chemical changeC

6.2 Rate of reaction

  • 6.2.1Rate factors: concentration, pressure, area, temperature, catalysts/enzymesC
  • 6.2.2Catalyst action and recoveryC
  • 6.2.3Rate measurements by mass loss or gas collectionC
  • 6.2.4Interpreting rate tables and graphsC
  • 6.2.5Collision model: density, frequency, kinetic energy, EaS
  • 6.2.6Collision explanations of all five rate factorsS
  • 6.2.7Catalyst and lower activation barrierS
  • 6.2.8Evaluating rate methodsS

6.3 Reversible reactions and equilibrium

  • 6.3.1Reversible-reaction notationC
  • 6.3.2Hydration/dehydration of copper sulfate and cobalt chlorideC
  • 6.3.3Dynamic equilibrium in a closed systemS
  • 6.3.4Equilibrium shifts: temperature, pressure, concentration, catalystS
  • 6.3.5Haber reaction equationS
  • 6.3.6Haber feedstock sourcesS
  • 6.3.7Haber operating conditionsS
  • 6.3.8Contact-process conversion equationS
  • 6.3.9Contact-process feedstock sourcesS
  • 6.3.10Contact-process operating conditionsS
  • 6.3.11Industrial compromise: yield, rate, safety, economicsS

6.4 Redox

  • 6.4.1Roman numerals in compound namesC
  • 6.4.2Coupled oxidation and reductionC
  • 6.4.3Oxygen-based oxidation/reduction definitionsC
  • 6.4.4Recognising oxygen-transfer redoxC
  • 6.4.5Identifying which species is oxidised/reducedC
  • 6.4.6Oxidation: electrons and oxidation-number increaseS
  • 6.4.7Reduction: electrons and oxidation-number decreaseS
  • 6.4.8Recognising electron-transfer redoxS
  • 6.4.9Oxidation-number rules for elements, ions and compoundsS
  • 6.4.10Redox colour evidence: permanganate and iodideS
  • 6.4.11Oxidising-agent roleS
  • 6.4.12Reducing-agent roleS
  • 6.4.13Agent identification in unfamiliar redoxS