Give reasons for the following: (a) When 30 mL of ethyl alcohol and 30 mL of water are mixed, the volume of resulting solution is more than 60 mL. (b) Copper is conducting as such while copper sulphate is conducting only in molten state or in aqueous solution.

Explanation

(a) It is because force of attraction between ethanol and `H_2O` is less, therefore, it shows +ve deviation from Raoult.s Law. `Delta V` = +ve.
(b) Copper is metal, has free electrons, therefore, conducts in solid state. Copper sulphate forms ions only in molten state or in aqueous solution. It is the ions which conduct electricity in copper sulphate.