Question

Name a substance which when dissolved in water contains

(i) Only ions

(ii) Ions and molecules.

Answer 1

(i) The substance which when dissolved in water contains only ions are strong electrolyte such as $\mathrm{HCl},{\mathrm{H}}_2{\mathrm{SO}}_{4,}\mathrm{NaOH}\mathrm{etc}$

$\mathrm{HCl}\left(\mathrm{l}\right)\stackrel{\mathrm{aq}}{\rightleftharpoons }{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)$

(ii)The substance which when dissolved in water contains both ions and molecules are weak electrolytes such as ${\mathrm{CH}}_3\mathrm{COOH},\mathrm{HCOOH},{\mathrm{H}}_2{\mathrm{CO}}_3\mathrm{etc}$

${\mathrm{CH}}_3\mathrm{COOH}\left(\mathrm{l}\right)\stackrel{\mathrm{aq}}{\rightleftharpoons }{\mathrm{CHCOO}}^{-}\left(\mathrm{aq}\right)\hspace{0.17em}+\hspace{0.17em}{\mathrm{H}}^{+}\left(\mathrm{aq}\right)$