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 $\mathrm{NH}_{4} \mathrm{Cl}=53.5 \mathrm{~g} \mathrm{~mol}^{-1}$ )