Chemistry - Ionic Equilibrium Question with Solution | TestHub

When a weak acid (acetic acid) and weak base$\left({\text{NH}}_{\text{4}}\text{OH}\right)$are mixed to form a solution.$\text{pH}$of the solution is then determined by following formula:

$\text{pH}\text{=}\text{7}\text{+}\frac{\text{1}}{\text{2}}\left[{\text{pK}}_{\text{a}}-{\text{pK}}_{\text{b}}\right]$

Given,${\text{pK}}_{\text{a}}\text{=}\text{4}\text{.76, }{\text{pK}}_{\text{b}}\text{=}\text{4}\text{.75}$

$\text{pH}\text{=}\text{7}\text{+}\frac{\text{1}}{\text{2}}\left[\text{4}\text{.76}-\text{4}\text{.75}\right]$

$\text{pH}\text{=}\text{7}\text{+}\text{0}\text{.005}$

$\text{pH}\text{=}\text{7}\text{.005}$