A clear, illustrated guide to the qualitative tests for carbonate, sulfate and halide ions, bringing three important anion tests together on one classroom-ready resource.

The poster shows the experimental procedure, observations and relevant ionic equations, helping students understand not only what to do, but why each test works.

It covers:

Carbonate ions, CO₃²⁻ – addition of dilute acid produces carbon dioxide, confirmed by passing the gas into limewater, which turns cloudy.
Sulfate ions, SO₄²⁻ – formation of a white precipitate of barium sulfate using acidified barium chloride solution.
Halide ions: Cl⁻, Br⁻ and I⁻ – acidification with dilute nitric acid followed by aqueous silver nitrate gives the characteristic white, cream and yellow silver halide precipitates. Their different solubilities in dilute and concentrated ammonia are also compared.

The resource includes ionic equations with state symbols and explains why the choice of acid matters in qualitative analysis. Students are prompted to consider why hydrochloric acid cannot be used before the silver nitrate test and why sulfuric acid could also interfere by forming a white silver sulfate precipitate.

The poster emphasises the connection between experimental observations and ion identification, rather than simply providing a list of tests to memorise.

Suitable for GCSE, IGCSE and A-level Chemistry, particularly for teaching qualitative analysis, practical preparation, revision and classroom display.

A QR code links to FranklyChemistry, where students can explore the corresponding animated experimental demonstrations and further chemistry resources.