An unknown salt contains a positive ion (a cation) and a negative ion (an anion). Each is found with its own test, and the two results are then put together to name the salt. Test the cation first, then the anion.
Cation results. Flame test: lithium red, sodium yellow, potassium lilac, calcium orange-red, copper blue-green. Sodium hydroxide solution: aluminium gives a white precipitate that dissolves in excess, calcium gives a white precipitate that does not dissolve in excess, copper gives a light blue precipitate, iron(II) gives a green precipitate, iron(III) gives a brown precipitate, and ammonium gives ammonia gas on warming, which turns damp red litmus paper blue.
Anion results. Carbonate: fizzes with dilute acid, giving carbon dioxide that turns limewater cloudy. Sulfate: dilute hydrochloric acid then barium chloride gives a white precipitate. Halides: dilute nitric acid then silver nitrate gives a white precipitate for chloride, a cream precipitate for bromide and a yellow precipitate for iodide.
Example: a salt gives a blue-green flame, a light blue precipitate with sodium hydroxide, and a white precipitate with nitric acid and silver nitrate. The cation is copper and the anion is chloride, so the salt is copper chloride. Always check that each result fits only one ion.