Explanation:
Strong electrolytes are those solutions which undergo complete dissociation when dissolved in water. The dissociation of strong electrolytes is given by a right arrow.
NaCl being an ionic compound dissociate in water to give sodium and chloride ions which help in conduction of electricity.
[tex]NaCl(aq)\rightarrow Na^+(aq)+Cl^-(aq)[/tex]
Whereas sugar being a covalent compound, do not dissociate into ions when dissolved in water and thus cannot conduct electricity.
