The degree of dissociation of $0.01 \ M$ solution of $NH_4OH$ is $4.2 \times 10^{-2}$. What is the percent dissociation of $NH_4OH$ (in $\%$)?

The hydrogen ion concentration in a mixture of $10 \ mL$ of $0.1 \ M$ $H_2SO_4$ and $10 \ mL$ of $0.1 \ M$ $KOH$ solution in water,is . . . . . . $M$.

Calculate the ionic product of the solution formed by mixing equal volumes of $0.004 \, M \, CaSO_4$ and $0.002 \, M \, H_2SO_4$.

At $60\,^{\circ}C$,the concentration of $[H_3O^{+}]$ in pure water is $10^{-6.7} \, \text{mol/L}$. What is the value of $K_W$ at $60\,^{\circ}C$?

Which of the following compounds are partially soluble or insoluble in $NH_4OH$ solution?
$(I)$ $Fe(OH)_3$
$(II)$ $Ag_2CrO_4$
$(III)$ $Al(OH)_3$
$(IV)$ $Ag_2CO_3$

The first and second ionization constants of a weak dibasic acid $H_{2}A$ are $8.1 \times 10^{-8}$ and $1.0 \times 10^{-13}$ respectively. $0.1 \text{ mol}$ of $H_{2}A$ was dissolved in $1 \text{ L}$ of $0.1 \text{ M}$ $HCl$ solution. The concentration of $HA^{-}$ in the resultant solution is: