Question

Citric acid, which is extracted from citrus fruits and pineapples, undergoes three successive deprotonations with pKa values of 3.14, 5.95, and 6.39. Estimate the pH of a 0.15 M aqueous solution of the monosodium salt.

a) 4.1

b) 6.5

c) 7.0

d) 5.0

Answer 1

The pH of a 0.15 M aqueous solution of the monosodium salt of citric acid would be around 4.1.

Step-by-step explanation:

The pH of a solution of the monosodium salt of citric acid can be estimated by considering the deprotonations of the citric acid. Since the pKa values of citric acid are 3.14, 5.95, and 6.39, we can determine the pH at which the ions are present in the solution. The monosodium salt is formed after the first deprotonation of citric acid, which has a pKa of 3.14. At this pH, the solution will be in the acidic range, so the pH of a 0.15 M aqueous solution of the monosodium salt would be around 4.1 (option a).