When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of:

Q. When $H_{2}S$ gas is passed through the blue solution of $CuS{O}_4$, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of

Q. When hydrogen sulfide gas is passed through a blue solution of copper sulfate, a black precipitate of copper sulfide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of:

Q. The reaction between iron and copper sulphate solution represents which type of reaction ?
(1) decomposition
(2) combination
(3) single displacement
(4) double decomposition

Q. When a piece of lead $\left(\text{Pb}\right)$ is left in blue coloured copper sulphate solution $\left({\text{CuSO}}_4\right)$, the colour of lead changes due to copper deposition. What type of reaction is this?

Q. A red-brown metal X forms a salt XSO₄. When hydrogen sulphide gas is passed through an aqueous solution of XSO₄, then a black precipitate of XS is formed alongwith sulphuric acid solution.
(a) What could the salt XSO₄ be?
(b) What is the colour of salt XSO₄?
(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?