Assertion : It is difficult to distinguish the strengths of the strong acids such as

                  $\mathrm{HCl}, {\mathrm{H}}_2{\mathrm{SO}}_4, {\mathrm{HNO}}_3, \mathrm{HBr}, \mathrm{Hl} \mathrm{or} {\mathrm{HClO}}_4$ in dilute aqueous solutions.

Reason : In dilute aqueous solution all strong acids donate a proton to water and are essentially.

               100% ionised to produce a solution containing ${\mathrm{H}}_3{\mathrm{O}}^{+}$ ions plus the anions of strong acid.

Assertion : 0.20 M solution of $\mathrm{NaCN}$is more basic than 0.20 M solution of $\mathrm{NaF}$.

Reason : 0.20 M solution of $\mathrm{NaCN}$ is more basic than 0.20 M solution of ${\mathrm{CH}}_3\mathrm{COONa}.$

Assertion: A substance that can either act as an acid or a base is called ampholyte.

Reason: Bisulphide ion $\left({\mathrm{HS}}^{-}\right)$ and bicarbonate ion $\left({{\mathrm{HCO}}_3}^{-}\right)$ are ampholytes.