Precipitation reactions

Precipitation- when you obtain an insoluble salt from a solution

Precipitation reactions can be used to identify different dissolved ions and can remove soluble metal ions from solutions

Mix together two solutions, then filter off the insoluble solid

End up with:

A solution of soluble products

An insoluble precipitate in the filter funnel

Precipitate test for metal ions:

Potassium ion- Lilac flame

Lithium ion- crimson flame

Calcium ion- orange/red flame

Copper ion- green flame

Sodium ion- yellow flame

Precipitate test for non-metal ions:

Sulfate- HCl + BaCl2 → white precipitate

Carbonate- HCl → CO2 gas produced

Chloride- HNO3 + AgNO3 → white precipitate

Bromide- HNO3 + AgNO3 → cream precipitate

Iodide- HNO3 + AgNO3 → yellow precipitate

Flame tests- identifies metal ions by the colours they produce when heated

Carbonate test- test for carbon dioxide by turning limewater cloudy

Sulfates test- barium chloride firms an insoluble white precipitate when sulfates are present

Halides test- halides produce silver coloured halide precipitates when reacted with silver nitrate solution