Module 3 - chapter 8 key terms Flashcards
Reducing agents
They reduce other species, by giving out one or more electrons, e.g group 2 elements
Oxidising agents
They oxidise other species by taking one or more electrons from them, so they themselves are reduced, e.g halogens
Disproportionation reaction
A reaction in which the same element is both oxidised and reduced, e.g chlorine with water or cold, dilute sodium hydroxide.
Qualitative analysis
Relies on simple observations rather than measurements.
Carbonate test
Carbonates react with acids (usually use dilute nitric acid) to form carbon dioxide (bubbles seen and it will turn limewater cloudy).
Sulfate test
Add barium nitrate (or barium chloride if you don’t wish to do a halide test afterward), if sulphates are present a white precipitate of barium sulphate will form.
Halide test
Add aqueous silver nitrate, if halides are present a precipitate will form. Silver chloride is white, silver bromide is cream-coloured and silver iodide is yellow.
Sequence of tests
Carbonate, sulphate, halide
