in phenoxide and acetate ion no. of canonical structures is same then why acetic acid is more acidic than phenol.

hi Somy ,

actually in acetate ion _ charge is distributed equally b/w the 2 oxygen atoms ,,, as this is more important ,,,

& the same is not possible in phenoxide ion,,,,so tats it..

good day , bye

In phenoxide ion, the -ve charge is delocalised over the benzene ring, but in acetate ion, it is delocalised on two oxygen atoms making them more -ve. So acetate ion is more -ve than phenoxide ion

IT IS NOT THE  RESONANCE STRUCTURES ALONE WHICH DETERMINE THE ACIDIC CHARACTER.  HERE THE RESONANCE STABILISATION OF ACETATAE ION IS MORE THAN PHENOXIDE ION.THEN ACETIC ACID HAS LOWER PKa value (5) than phenol(10).