$A$ certain amount of $H_2CO_3$ and $HCl$ are dissolved to form $1 \ L$ solution. At equilibrium,it is found that the concentrations of $H_2CO_3$ and $CO_3^{2-}$ are $0.1 \ M$ and $0.01 \ M$ respectively. Calculate the $pH$ of the solution. Given that for $H_2CO_3$,$K_{a_1} = 10^{-5}$ and $K_{a_2} = 10^{-8}$.

Blue litmus turns red in the following mixture of acid and base:

If $20 \, mL$ of $0.25 \, N$ strong acid and $30 \, mL$ of $0.2 \, N$ strong base are mixed,then the resulting solution is

An acid dissociated to $1.5 \%$ in its $0.1 \ M$ solution. Calculate its dissociation constant.

$A$ weak acid is titrated with a weak base. Consider the following statements regarding the $pH$ of the solution at the equivalence point.
$(i)$ $pH$ depends on the concentration of acid and base
$(ii)$ $pH$ is independent of the concentration of acid and base
$(iii)$ $pH$ depends on the $pK_{a}$ of acid and $pK_{b}$ of base
$(iv)$ $pH$ is independent of the $pK_{a}$ of acid and $pK_{b}$ of base
The correct statements are

$0.1 \ M$ solution of which of the following has almost unity degree of dissociation?