Question

ethanoic acid is a weaker acid than benzoic acid.??

Answer 1

Electron withdrawing groups increase the acidity of carboxylic acids by stabilising the conjugate base through delocalisation of the negative charge by inductive and/or resonance effects. Due to the presence of benzene ring in benzoic acid, delocalisation of electron makes it more acidic than ethanoic acid but such stabilization is not present in ethanoic acid, as in benzoic acid the cleavage of O-H bond becomes easy due to delocalization of the charge on the benzene ring.