What is the approximate buffering range of formic acid? a. you have a formic acid/potassium formate solution that has a ph of 4.75. what is the ratio of the formate to the formic acid? b.

a. The buffering range is between 2.74 and 4.74.

b. The ratio of the formate to the formic acid is 10.23.

Explanation:

a. For every buffer solution, the optimal effective range is pH = pKa ± 1. Outside this range, the buffer does not work properly.

For the formic acid, the pKa is 3.74, thus the optimal range is between 2.74 and 4.74.

b. The Henderson-Hasselbalch equation is a chemical expression used to calculate the pH of a buffer knowing the ratio of the acid to base, or to calculate the ratio knowing the pH. The expression is:

where [A^{-}] is the concentration of the conjugate base and [HA] is the concentration of the acid.

For a formic acid/potassium formate solution that has a pH of 4.75 and pka of 3.74:

b.final