The K_afor formic acid (HCO₂H) is 1.8 × 10^-⁴. What is the pH of a 0.35 M aqueous solution of sodium formate (NaHCO₂)?

Question

Quizplus · Accepted Answer

Sodium formate is the salt of a weak acid (formic acid) and a strong base (sodium hydroxide). In solution, it hydrolyzes to form a basic solution. The pH can be calculated using the formula pH = 14 - pKa + log([A-]/[HA]), where [A-] is the concentration of the formate ion. Given the K_a of formic acid, the pKa is approximately 3.74. The solution is basic, so the pH is greater than 7, making 8.6 the correct choice.

The Ka for Formic Acid (HCO2H) Is 1

The K_afor Formic Acid (HCO₂H) Is 1