Chapter 14, Problem 61E

Propionic acid, ${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{CO}}_{\text{2}}{\text{H(K}}_{\text{a}}\text{= 1}\text{.34 }\times {\text{ 1O}}^{\text{-5}}\text{),}$ is used in the manufacture of calcium propionate, a food preservative. What is the pH of a 0.698-M solution of ${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{CO}}_{\text{2}}\text{H?}$