The pKa of lactic acid is 3.9.A lactate buffer will be useful from pH values

Question

Quizplus · Accepted Answer

The pH range for a buffer solution is typically defined as the pKa ± 1. For the given pKa value of lactic acid, the pH range for a lactate buffer would be: pH = pKa + log([salt]/[acid]) pH = 3.9 + log([salt]/[acid]) At pH 2.9: pH < pKa - 1, so [acid]/[salt] > 10. At pH 4.9: pH > pKa + 1, so [acid]/[salt] < 0.1. Therefore, the useful pH range for a lactate buffer solution would be from 2.9 to 4.9, but the most appropriate answer is C because it is the only choice that includes the pKa value + 1 on either side of the range.

The PKa of Lactic Acid Is 3