Calculate the value of the dissociation constant $(K_a)$ of a weak acid,which dissociates to $0.01 \%$ in its $0.1 \ M$ solution.

The $K_b$ of ammonia $(NH_3)$ is $1.8 \times 10^{-5}$ at $298 \ K$. Calculate the $pH$ of a $0.1 \ M$ ammonia solution. (in $.13$)

Calculate $[H_3O^{+}]$ in $0.02 \ M$ solution of monobasic acid if dissociation constant is $1.8 \times 10^{-5}$.

What is the percent dissociation of acetic acid in its $0.01 \ M$ solution if the dissociation constant of the acid is $1.34 \times 10^{-6}$ (in $\%$)?

The $pH$ of $0.1 \ M$ monobasic acid is $4.50$. Calculate the concentration of species $H^{+}$,$A^{-}$ and $HA$ at equilibrium. Also,determine the value of $K_{a}$ and $pK_{a}$ of the monobasic acid.

The degree of ionization of $0.10 \ M$ lactic acid is $4.0 \%$. The value of $K_a$ is: