Question

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:

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

Answer 1

The correct option is D A double displacement reaction

A double displacement reaction is a type of reaction where part of one reactant is replaced by part of another reactant.
$CuS{O}_4+H_{2}S\to CuS+H_{2}S{O}_4$