Question

Which of the following compound will have the smallest $p{K}_a$ value ?

• A. Benzoic acid
• B. Formic acid
• C. Acetic acid
• D. Phenylacetic acid

Answer 1

Answer: (B)

Smaller the $p{K}_a$ value stronger is the acid. As, out of the given acids, formic acid is the strongest acid, its $p{K}_a$ will be smallest