Chapter 16, Problem 94GQ

Pyridine is weak organic base and readily forms a salt with hydrochloric acid.

$\begin{array}{l}{\text{C}}_{\text{5}}{\text{H}}_{\text{5}}\text{N(aq) + HCl(aq) }\to {\text{ C}}_{\text{5}}{\text{H}}_{\text{5}}{\text{NH}}^{\text{+}}{\text{(aq) + Cl}}^{-}\text{(aq)}\\ \text{ Pyridine Pyridinium ion}\end{array}$

What is the pH of a 0.025 M solution of pyridinium hydrochloride ${\text{[C}}_{\text{5}}{\text{H}}_{\text{5}}{\text{NH}}^{\text{+}}{\text{]Cl}}^{-}$?