$A$ sample of $Na_2CO_3 \cdot H_2O$ weighing $0.62 \ g$ is added to $100 \ mL$ of $0.1 \ N \ (NH_4)_2SO_4$ solution. What will be the nature of the resulting solution?

The species present in solution when $CO_2$ is dissolved in water are

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

At $25\, ^oC$,the dissociation constant of $CH_3COOH$ and $NH_4OH$ in aqueous solution are almost the same. The $pH$ of a $0.01\, N$ $CH_3COOH$ solution is $4.0$ at $25\, ^oC$. The $pH$ of a $0.01\, N$ $NH_4OH$ solution at the same temperature would be:

The $pH$ of a solution obtained by mixing $50 \, mL$ of $1 \, M \, HCl$ and $30 \, mL$ of $1 \, M \, NaOH$ is $x \times 10^{-4}$. The value of $x$ is ...... . (Nearest integer) $[\log 2.5 = 0.3979]$

The $pH$ of the solution containing $10 \ mL$ of $0.1 \ N$ $NaOH$ and $10 \ mL$ of $0.05 \ N$ $H_2SO_4$ would be