The test tube being workedReagents in labelled dropping bottlesBlack epoxy benchSalt analysis. A salt is made of a cation (from the base) and an anion (from the acid). First the preliminary tests: colour, smell, whether it dissolves (the original solution), and the flame test. Then the anion: dilute sulphuric acid on the salt (a carbonate fizzes, and the carbon dioxide turns lime water milky), concentrated sulphuric acid (a chloride gives HCl, white fumes with ammonia; a nitrate gives brown fumes), and the confirmatory tests: barium chloride for sulphate (white precipitate), silver nitrate for chloride (curdy white, soluble in ammonia), the brown ring for nitrate. Then the cation: ammonium with sodium hydroxide (zero group), then groups I to VI with their group reagents in order (dil. HCl, H₂S in acid, NH₄Cl + NH₄OH, H₂S in ammonia, ammonium carbonate, disodium hydrogen phosphate), stopping at the group that gives a precipitate, and its confirmatory test. Each change you see is ions meeting: when their product is insoluble they leave the solution as a solid of their own colour.