Question

(a) Barium chloride reacts with aluminium sulphate to give aluminium chloride and barium

sulphate.

(i) State the type of reaction.

(ii) Translate the above statement into a balanced chemical equation.

(b) A metal ‘X’ acquires a green colour coating on its surface on exposure to air.

(i) Identify the metal ‘X’ and name the process responsible for this change.

(ii) Name and write the chemical formula of the green colour coating formed on the surface

of the metal​

Answer 1

Answer:

A balanced equation for "Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate" is as follows :

3Bacl2 (aq) + Al2(So4)3 (aq) ⇒ 2AlCl3 (aq) + 3BaSo4 (s)

The reaction is double displacement reaction, since the ions of two reactants are exchanged to form two new compounds. The reaction is also called as precipitation reaction as a precipitate of barium sulphate is being formed.

(i) Metal is copper. The process is corrosion.

(ii)2Cu + H2O + Co2 + O2 ⇒ Cu(OH)2CuCo3

Basic copper carbonate [CuCO3.Cu(OH)2].