Question

Give a reason for the following observation

An aqueous solution of common salt conducts electricity whereas, that of sugar does not.

Answer 1

An aqueous solution of common salt conducts electricity whereas, that of sugar does not.

• An aqueous solution of common salt is a solution of sodium chloride.
• The sodium chloride$\left(\mathrm{NaCl}\right)$ will dissociate into sodium ions$\left({\mathrm{Na}}^{+}\right)$ and chloride ions$\left({\mathrm{Cl}}^{-}\right)$. These ions will be responsible for electrical conductivity.

$\underset{\mathrm{Sodium}\mathrm{chloride}}{\mathrm{NaCl}\left(\mathrm{s}\right)}\stackrel{\left[\mathrm{aq}\right]}{\rightleftharpoons }\underset{\mathrm{Sodium}\mathrm{ion}}{{\mathrm{Na}}^{+}}+\underset{\mathrm{Chloride}\mathrm{ion}}{{\mathrm{Cl}}^{-}}$

• An aqueous solution of sugar solution contains sugar molecules only, it does not dissociate into its constituent ions. hence there are no ions, it does not conduct electricity.
• The chemical fomula of sugar is ${\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}$ it does not dissociate when it is dissolved in water, hence it does not conduct electricity.