GCSE Chemistry
Chemical Analysis
Chemical Analysis is a core strand in Chemistry. Work through the topics below in any order, or follow your course — each guide includes explanations, common mistakes and exam-style practice.
Topic guides
Pure Substances & Formulations
A pure substance consists of only one element or one compound.
Open guideChromatography
Chromatography is a technique used to separate a mixture of soluble substances.
Open guideTesting Gases
Chemists use specific chemical tests to identify common gases.
Open guideTests for Positive Ions
Positive metal ions (cations) in a solution can be identified by adding a few drops of sodium hydroxide solution.
Open guideTests for Negative Ions
Negative ions (anions) can also be identified using specific chemical tests.
Open guideFlame Tests
Flame tests are used to identify some metal ions (cations) by the characteristic colour they produce when heated in a flame.
Open guide
Revision strategy
Students often slip on the details explained in our guides — read the “common mistakes” section in each topic.
- Alternate between reading a guide and doing timed questions — don’t only re-read notes.
- Return to this hub anytime; new guides appear automatically as we publish them.