Contents

States of matter

Atoms, elements and compounds

Stoichiometry

Electrochemistry

ElectrolysisBeing prepared
Electrolysis of solutions and electroplatingBeing prepared
Fuel cellsBeing prepared

Chemical energetics

Chemical reactions

Acids, bases and salts

Acids, bases and indicators
OxidesBeing prepared
Making saltsBeing prepared

The Periodic Table

Reading the tableBeing prepared
Group I: the alkali metalsBeing prepared
Group VII: the halogensBeing prepared
Transition elements and noble gasesBeing prepared

Metals

Metals and alloysBeing prepared
The reactivity seriesBeing prepared
CorrosionBeing prepared
Extracting metalsBeing prepared

Chemistry of the environment

WaterBeing prepared
FertilisersBeing prepared
Air quality and climateBeing prepared

Organic chemistry

Naming organic moleculesBeing prepared
Crude oil and alkanesBeing prepared
AlkenesBeing prepared
Alcohols and carboxylic acidsBeing prepared
PolymersBeing prepared

Experimental techniques and chemical analysis

Mixtures and separation
Measuring and planning experimentsBeing prepared
Crystallisation
Distillation
Paper chromatography
Choosing methods and checking purityBeing prepared
TitrationBeing prepared
Gas testsBeing prepared
Anion testsBeing prepared
Cation and flame testsBeing prepared

Part 3 of 3

Page 03

Two colour tests

state

Try it yourself

Supplement. Match each solution to its colour.

state: give a concise answer.

Match each item

1. Acidified potassium manganate(VII), before the test

2. Acidified potassium manganate(VII), after a reducing agent is added

3. Aqueous potassium iodide, before the test

4. Aqueous potassium iodide, after an oxidising agent is added

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Scope and sources

Cambridge IGCSE Chemistry 0620 · 2026–2028 v2 · Original learning materials.

Redox (6.4 Core 1 to 5; Supplement 6 to 13): oxidation numbers from Roman numerals, oxidation and reduction as gain and loss of oxygen, of electrons and as changes in oxidation number, oxidising and reducing agents, and the colour tests with acidified potassium manganate(VII) and potassium iodide. Half-equations are in ELYS01, the reactivity series and displacement in REACT01, and the extraction of metals in EXTR01.

Apparatus, amounts and times in the experiment are illustrative. Real practical work follows a teacher-approved safety method.

Official Cambridge syllabus