Chapter 16, Problem 16.67SP

Which of the following gives a buffer solution when equal volumes of the two solutions are mixed?

(a) 0.10 M ${\text{NH}}_{\text{3}}$ and 0.10 M HCl

(b) 0.20 M ${\text{NH}}_{\text{3}}$ and 0.10 M HCl

(c) 0.10 M ${\text{NH}}_{\text{4}}\text{Cl}$ and 0.10 M ${\text{NH}}_{\text{3}}$

(d) 0.20 M ${\text{NH}}_{\text{4}}\text{Cl}$ and 0.10 M NaOH