Question

Give reasons why :
(i) Sodium Chloride will conduct electricity only in fused or aqueous solution state.
(ii) In the electroplating of an article with silver, the electrolyte sodium argento-cyanide solution is preferred over silver nitrate solution.
(iii) Although copper is a good conductor of electricity, it is a non-electrolyte.

Answer 1

(i) Sodium chloride does not have any free mobile ions in its solid state which are responsible for the conduction of electricity but in fused or aqueous state it conducts electricity as it has free mobile ions in that state.

(ii) If the solution used as electrolyte is sodium nitrate then this solution of sodium nitrate undergoes rapid dissociation which does not results in the uniform coating over the article. Hence, sodium argento-cyanide is used as electrolyte as it being an complex salt undergoes slow dissociation and we can ensure uniform and perfect coating over the article.

(iii) We know that copper is a metal and metals are the good conductors of electricity as so is copper. But copper does not have ions in it so it is a non electrolyte.