19. Assertion (A): The colour of aqueous solution of copper sulphate turns colourless when a piece of lead is added to i

Ans. (a) Both (A) and (R) are true, and (R) is the correct explanation of (A).

Explanation: The colour of a copper sulphate aqueous solution turns colourless when a piece of lead is added to it. Compared to copper, lead is more reactive, as a result, copper gets displaced from its salt solution. The following reaction occurs:

$$\mathrm{Pb}_{(x)} + \mathrm{CuSO}_{4(aq)} \longrightarrow \mathrm{PbSO}_{4(x)} + \mathrm{Cu}_{(x)}$$