Ionic Equilibrium

Class XII students were asked to prepare one litre of buffer solution of \(\mathrm{pH} \,8.26\) by their Chemistry teacher: The amount of ammonium chloride to be dissolved by the student in \(0.2\, \mathrm{M}\) ammonia solution to make one litre of the buffer is :

(Given: \(\mathrm{pK}_{\mathrm{b}}\left(\mathrm{NH}_{3}\right)=4.74\)

Molar mass of \(\mathrm{NH}_{3}=17 \mathrm{~g} \mathrm{~mol}^{-1}\)

Molar mass of \(\mathrm{NH}_{4} \mathrm{Cl}=53.5 \mathrm{~g} \mathrm{~mol}^{-1}\) )