Problem: What is the ratio of [A–]/[HA] at pH 5.75? The pKa of formic acid (methanoic acid, H–COOH) is 3.75.Draw the structure for formic acid.Draw the structure of the conjugate base for formic acid.

FREE Expert Solution

a) From the Henderson-Hasselbalch equation:


pH=pKa+log[A-][HA]


where [HA] = formic acid

[A] = formate

pKa = 3.75

pH = 5.75

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Problem Details

What is the ratio of [A–]/[HA] at pH 5.75? The pKa of formic acid (methanoic acid, H–COOH) is 3.75.

Draw the structure for formic acid.

Draw the structure of the conjugate base for formic acid.

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