clean a platinum wire loop by dipping it in some dilute HCL and then holding it in a blue flame from a Bunsen burner until it burns without any colour
Then, dip the loop into the sample you want to test and put it back into the flame. Record the colour of the flame.
Flame tests only work for samples that contain a single metal ion.
If the sample tested contains a mixture of metal ions, the flamecolours of some ions may be hidden (masked) by the colours of others
Some metals form a coloured precipitate with NaOH. Adding a few drops of sodium hydroxide sometimes form specific coloured precipitates
When testing for sulfates, you add HCL (as well as barium chloride), to get rid of any traces of carbonateions before you do the test. These would also produce a precipitate, so they'd confuse the results.
An impure substance is a substance made up of two or more elements or compounds that are not bonded together chemically
A precipitate is a solid that is created from a solution during a reaction
Aluminium, calcium and magnesium ions form a white precipitate with NaOH
Only aluminium's precipitate dissolves when excess NaOH is added to the solution
Copper(II) produces a blue precipitate
Iron (II) produces a green precipitate
Iron(III) produces a brown precipitate
When you add a hydroxide to a metal, the half equation always is:
Metal ion + Hydroxide ion -> MetalHydroxide
Carbonates react with diluteacids to create carbon dioxide
To test for halides first add nitric acid, followed by silver nitrate solution