Which of the following will produce a buffer solution when mixed in equal volumes?

Question

Professor PC Thomas Classes · Answer

(c) : In $0.1 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{NH}_4 \mathrm{OH}$ and $0.05 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{HCl}$, total amount of HCl reacts with $\mathrm{NH}_4 \mathrm{OH}$ to form $\mathrm{NH}_4 \mathrm{Cl}$ and some $\mathrm{NH}_4 \mathrm{OH}$ will be left unreacted. Thus, the resultant solution contains $\mathrm{NH}_4 \mathrm{Cl}$ and $\mathrm{NH}_4 \mathrm{OH}$ which will produce a buffer solution.