Question

The reaction given below is an example of:
${\text{CuSO}}_4\text{(aq)}+{\text{H}}_2\text{S(g)}\to \text{CuS(s)}$ $\downarrow$ + ${\text{H}}_2{\text{SO}}_4\text{(aq)}$

• A. combination reaction
• B. displacement reaction
• C. decomposition reaction
• D. double displacement reaction

Answer 1

The correct option is D double displacement reaction

In the given reaction, there is exchange of ions between copper sulphate (${\text{CuSO}}_4$) and hydrogen sulphide (${\text{H}}_2\text{S}$). Sulphuric acid (${\text{H}}_2{\text{SO}}_4$) and the precipitate of copper sulphide ($\text{CuS}$) are formed. Such kind of reaction in which there is exchange of ions between the reactants in order to form new products is called double displacement reaction. This reaction is also an example of a precipitation reaction as the precipitate of copper sulphide is formed