Among the following acids which has the lowest pKa value

• Equilibrium

Among the following acids which has the lowest pKa value?

1. HCOOH
2. CH₃CH₂COOH
3. (CH₃)₂CH–COOH
4. CH₃COOH

Answer

Higher the pK_a value, weaker is the acid. Hence, strongest acid has lowest pK_a value.

The correct option is C.