Precipitate

Key Stage 4

A precipitate of Lead Iodide formed in the reaction between Lead Nitrate and Potassium Iodide.

Meaning

A precipitate is a solid insoluble compound formed by the chemical reaction between two other chemicals in solution.

About Precipitates

The reactants in a precipitation reaction are aqueous or gaseous but at least one of the products is an insoluble solid.

Some common precipitate reactions you may know are:

Lead Nitrate + Potassium Iodide → Potassium Nitrate + Lead Iodide

\(Pb(NO_3)_2(aq) + 2KI(aq) → 2KNO_3(aq) + PbI_2(s)\)

Calcium Oxide + Carbon Dioxide → Calcium Carbonate

\(CaO(aq) + CO_2(g) → CaCO_3(s)\)

References

AQA

Precipitate, precipitation, pages 195, 210, 200, 263, 276-9, GCSE Chemistry; Student Book, Collins, AQA

Precipitate. Precipitation; gelatinous, page 276, GCSE Chemistry; Student Book, Collins, AQA

Precipitates, page 141, GCSE Combined Science; The Revision Guide, CGP, AQA

Precipitates, pages 69, 70, 88, 89, GCSE Chemistry; The Revision Guide, CGP, AQA

Edexcel

Precipitates, page 14, GCSE Biology, Pearson, Edexcel

Precipitates, pages 14, 68, 74, 196, GCSE Chemistry, Pearson, Edexcel

OCR

Precipitates, pages 90, 95, 276, Gateway GCSE Chemistry, Oxford, OCR