Formic acid is a weak acid along with a pKa of 3.75. The name comes by the Latin term "formica" ("ant") since this is very plentiful into the secretions of several species of ants, and is exact of the irritants delivered by several stinging ants, wasps and bees.
Assume that using of formic acid as the origin for a buffer for biochemical investigation. Would this be most useful for making a buffered solution at pH 2, 4, or 6? Briefly describe your answer.
Ans:
At pH 4 is useful to make a buffered solution: It is near the pKa. Therefore, there will be sufficient amounts of both conjugate acid and conjugate base to function as an effective buffer.