Chapter 16, Problem 16.91SP

Lactic acid ${\text{(C}}_{\text{3}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\text{)}$ , which occurs in sour milk and foods such as sauerkraut, is a weak mnonprotic acid. The pH of a 0.10 M solution of lactric acid is 2.43. What are the value of ${\text{K}}_{\text{a}}$ and ${\text{pK}}_{\text{a}}$ for lactic acid?