[Woopy]

Hello,

I am wondering why benzoic acids with electron donating groups worsen the acidity of the benzoic acid? If I draw out the resonance hybrid, there is a lot of partial negative charges around the atom, so isn't electron density being taken further away from the hydrogen attached to the oxygen on the carboxylic acid?

Likewise for an electron withdrawing group, there are a lot of partial positive charges on the resonance hybrid, so there is more electron density near the same hydrogen on the carboxylic acid.

I can't justify to myself why the electron donating group produces a weaker acid.

Thanks!

[Schrödinger]

Maybe looking at the conjugate base's stability might help. What happens to the benzoate ion in either case?

[Dan]

This topic is covered in all organic chemistry textbooks.