Aluminium
The Blast Furnace
Purification of Copper
Crude Oil
Electrolysis
Analysing Gases
Haber Process
Solubility of Salts
Steel
Test for Anions
Test for Cations
Titration

Other Section

Applied
Fundamental
Inorganic
Organic
Physical

Carbonate

Ion CO₃^2-, carbonate is found in limestone, or calcium carbonate (CaCO₃).

To test for it, you must first: Add a dilute acid to the sample. A gas is given off which when tested, should prove to be carbon dioxide.

Sulphate and Sulphide

Sulphate is SO₄^2- and
Sulphide is SO₃^2-

Adding barium chloride to the solution you are testing a white precipitate will form. If you add hydrochloric acid, the sulpahte (SO₄^2-) WILL NOT dissolve and the sulphite (SO₃^2-) will.

Halogen Tests

The test for halogens, or halide ions, is to add silver nitrate to a solution. We often add some nitric acid first as well. If there are chloride, bromide or iodide ions in the soltion they will react with silver to form a precipitate. The different precipitates are summarised in the table below.

The ionic equations for these reactions are:

Ag⁺ (aq) + Cl^- (aq) AgCl (s)
Ag⁺ (aq) + Br^- (aq) AgBr (aq)
Ag⁺ (aq) + I^- (aq) AgI (aq)