Question

Which of the two structures (A) and (B) given below is more stabilised by resonance ? Explain
`underset((A))(CH_(3)COOH)" "` and `" "underset((B))(CH_(3)COO^(-))`

Answer 1

Both `CH_(3)COOH` and `CH_(3)Cooverset(Θ)(O)` ion exhibit resonance as follows :

Structure (B) is more resonance stabilised since both the contributing structures for the carboxylate ion are equivalent.
Structure [A] is comparatively less stabilised since the contributing structures for the carboxylic acid are not equivalent.