A red-brown metal X forms a salt `XSO_(4)` . When hydrogen sulphide gas is passed through an aqueous solution of `XSO_(4)` , then a black precipitate of XS is formed along with sulphuric acid solution.
(a) What could the salt `XSO_(4)` be
(b) What is the colour of salt `XSO_(4)` ?
(c) Name the black precipitate XS.
(d) By using the formula of the salt obtained in (a) above , write an equation of the reaction which takes place when hydrogen sulphide gas is passed through its aqueous solution.
(e) What type of chemical reaction takes place in this case ?

Answer

(a) Copper sulphate (b) Blue colour (c) Copper sulphide (d) `CuSO_(4)` (aq) + `H_(2)S (g) to CuS (s) + H_(2)SO_(4)(aq)` (e) Double displacement reaction