Calculate $\left[ {{S^{ - 2}}} \right]$ and $\left[ {H{S^{ - 2}}} \right]$ of the solution which contain$0.1$ $M$ ${H_2}S$ and $0.3$ $M$ $HCl$.

[ ${H_2}S$ of ${K_a}\left( 1 \right) = 1.0 \times {10^{ - 7}}$ and ${K_a}\left( 2 \right) = 1.3 \times {10^{ - 13}}$ ]

The molar conductivity of a solution of a weak acid $HX (0.01\ M )$ is $10$ times smaller than the molar conductivity of a solution of a weak acid $HY (0.10 \ M )$. If $\lambda_{ X }^0 \approx \lambda_{ Y ^{-}}^0$, the difference in their $pK _{ a }$ values, $pK _{ a }( HX )- pK _{ a }( HY )$, is (consider degree of ionization of both acids to be $\ll 1$ )

Write characteristic and uses of weak base equilibrium constant ${K_b}$.

If the dissociation constant of an acid $HA$ is $1 \times {10^{ - 5}},$ the $pH$ of a $ 0.1$  molar solution of the acid will be approximately

The hydrogen ion concentration of $0.1\,N$ solution of $C{H_3}COOH,$ which is $30\%$ dissociated, is

The $pH$ of $ 0.1 \,M$  solution of a weak monoprotic acid  $1\%$  ionized is