The higher electronegativity of sp² hybridized carbon in phenol, compared to the sp³ hybridized carbon in alcohols, contributes to the increased acidity of the O-H bond in phenol. In phenol, the oxygen’s lone pair is more effectively delocalized into the aromatic ring due to the greater electronegativity of the sp² carbon. This resonance stabilization enhances the stability of the resulting phenoxide ion, making it easier for phenol to donate a proton. In contrast, the oxygen lone pair in alcohols is less efficiently delocalized, making the O-H bond in alcohols less acidic than that in phenol.