Chemistry - GOC Question with Solution | TestHub

All four conjugate bases are phenoxides; fluorine is electron-withdrawing by induction and stabilises the negative charge, so all three fluorophenols are stronger acids than phenol. The stabilisation is strongest at the ortho position (closest to ${\mathrm{O}}^{-}$), weaker at meta (induction only) and weakest at para, where fluorine's lone-pair donation partly offsets it. Order : o-fluorophenol $>$ m-fluorophenol $>$ p-fluorophenol $>$ phenol, i.e. b $>$ c $>$ d $>$ a. ($\mathrm{p}{K}_{\mathrm{a}}$ : 8.7, 9.3, 9.9, 9.95.)