(a) Acetic acid is a stronger acid than ethyl alcohol because the acetate ion formed by ionisation is stabilized by resonance while the ethoxide ion has no resonance. The negative charge in acetate ion formed by ionisation is stabilized by resonance while thw ethoxide ion has no resonance. The negative charge in acetate ion is delocalized over two oxygen atoms while the negative charge in ethoxide ion is localized on the single oxygen atom.
Hence, `CH_(3)COO^(-)` ion is more stable and a weaker base than `CH_(3)CH_(2)O^(-)` ion. As a weaker base has a stronger conjugate acid, `CH_(3)COOH` is a stronger acid than `CH_(3)CH_(2)OH`.
(b) Electron withdrawing groups (EWG) decrease the negative charge on the carboxylate ion and stabliseit, ie., loss of proton becomes relatively easy. Three chlorine atoms are electro withdrawing substituents (-I effect) in in trichloro acetic acid and thus, it is a stronger acid than acetic acid.
