Question

ethanoic acid is a weaker acid than benzoic acid . why

Answer 1

 This is due to stronger acids have lower pKa value.The ethanoic acid(pKa=476)is a weaker acid than benzoic acid(pKa=4 19)arcic;
 There is electron withdrawing groups which increase the acidity of carboxylic acids by stabilising the conjugate base through delocalisation of the negative charge by inductive & resonance effects.The presence of benzene ring in benzoic acid,delocalisation of electron make it more acidic than ethanoic acid but such stabilization is not present in ethanoic acid.