Test with Sulphate Ions
- Out of the 10 cations, only calcium ions and lead(II) ions will form a precipitate with sulphate ions.
- This is because both calcium sulphate and lead(II) sulphate are insoluble in water.
- The chemical reaction is a double decomposition reaction.Pb2+ + SO42- → PbSO4
Ca2+ + SO42- → CaSO4
H2SO4 or Na2SO4 | |
Na+ | – |
Ca2+ | White precipitate. |
Mg2+ | – |
Al3+ | – |
Zn2+ | – |
Pb2+ | White precipitate. |
Fe2+ | – |
Fe3+ | – |
Cu2+ | – |
NH4+ | – |