When a salt of weak acid and weak base is dissolved in water, the pH of the resulting solution will be:

For weak acid and weak base salts

Hydrolysis constant $\left({\mathrm{K}}_{\mathrm{h}}\right)=\frac{{\mathrm{K}}_{\mathrm{w}}}{{\mathrm{K}}_{\mathrm{a}}\times {\mathrm{K}}_{\mathrm{b}}}$,

Degree of hydrolysis $\mathrm{h}=\sqrt{{\mathrm{K}}_{\mathrm{h}}}=\sqrt{\frac{{\mathrm{K}}_{\mathrm{w}}}{{\mathrm{K}}_{\mathrm{a}}\times {\mathrm{K}}_{\mathrm{b}}}}$ when $\mathrm{h}<<1$

$\mathrm{pH}=\frac{1}{2}\left[{\mathrm{pk}}_{\mathrm{w}}+{\mathrm{pk}}_{\mathrm{a}}-{\mathrm{pk}}_{\mathrm{b}}\right]$