If $pK_{a} = -\log K_{a} = 4$ for a weak acid $HX$ and $K_{a} = C\alpha^{2}$,then the Van't Hoff factor when $C = 0.01 \ M$ is

The $pK_{b}$ of dimethylamine and $pK_{a}$ of acetic acid are $3.27$ and $4.77$ respectively at $T(K)$. The correct option for the $pH$ of dimethylammonium acetate solution is :

When $100 \ mL$ of $0.1 \ M$ $NaCN$ solution is titrated with $0.1 \ M$ $HCl$ solution,the variation of $pH$ of the solution with the volume of $HCl$ added will be:

The $pH$ of $0.1 \ M$ solution of the following salts increases in the order:

One mole of ammonia was completely absorbed in one litre solution each of $(a)$ $1 \ M \ HCl$,$(b)$ $1 \ M \ CH_{3}COOH$,and $(c)$ $1 \ M \ H_{2}SO_{4}$ at $298 \ K$. The decreasing order for the $pH$ of the resulting solutions is (Given $pK_{b}(NH_{3}) = 4.74$)

$20 \ mL$,$0.1 \ M \ HA$ $[(K_b)_{A^-} = 10^{-10}]$ is titrated against $0.2 \ M \ NaOH$. Select the correct statement [Given : $\log 2 = 0.3, \log 3 = 0.48$ ]