The carbon-oxygen bond in phenol is slightly stronger han that in methanol. Why ?


Positive resonance effect is observed in phenols. Due to this + R effect, lone pair of electrons of —OH group are in conjugation with π electrons of the ring and the following resonance hybrid are obtained.

 

From the above resonating structure, it is very clear that C—O bond of phenol acquires some partial double bond character while the C—O bond of methanol is purely single bond. Therefore, the carbon-oxygen bond in phenol is slightly stronger than that in methanol.