A buffer solution is prepared by mixing 0.01 M HCN and 0.02 MNaCN . If $\mathrm{K}_{\mathrm{a}}$ for HCN is $6.6 \times 10^{-10}$, what is the concentration of $\mathrm{H}^{+}$ions in solution?

A monobasic acid is $5 \%$ dissociated in its 0.02 M solution. Calculate the dissociation constant of acid.

Which among the following salts turns red litmus blue in its aqueous solution?

Calculate dissociation constant of a weak monobasic acid if it is $0.05 \%$ dissociated in 0.02 M solution.