Name the gas evolved when sodium hydroxide solution is warmed with an ammonium salt, and state how it is identified.

State the observations when sodium hydroxide solution is added, first a little and then in excess, to zinc sulphate solution, and write the equations.

A white precipitate is formed when sodium hydroxide is added to a salt solution, and it does not dissolve in excess. Name the cation and state one further test.

A salt solution gives a dirty green precipitate with sodium hydroxide solution, insoluble in excess. Identify the cation and write the equation for the reaction.

A salt solution gives a white precipitate with sodium hydroxide solution which dissolves in excess to give a colourless solution. Identify the two cations this could be and state how ammonium hydroxide distinguishes between them.

State what is observed when ammonium hydroxide solution is added, first a little and then in excess, to a solution of copper(II) sulphate.

Name the gas evolved when dilute hydrochloric acid is added to a carbonate, and state how it is identified.