Question

Compare acidity of phenol with that of ethanol and water

Answer 1

1-Comparison of acidic character of phenol and ethanol:

(Explanation using conjugate acid and base pair concept)

If we compare stabilities of ethanoxide & phenoxide then phenoxide is more stable due to resonance. As show in attached file.

So, it is weaker Conjugate base than ethanoxide( as if a base is more stable it is less likely to accept the proton and transfer into conjugate acid i.e it is a weaker base). Hence it conjugate acid phenol is stronger acid than ethanol(as stronger the conjugate base , stronger will be it's conjugate acid).

2-Comparison of acidic character of phenol and water-

When phenol donates the H+ ion it form phenoxide ion which is stable due to resonance as the negative charge is delocalised over benzene ring . Whereas in water ,after donation of H+ ion it forms OH- which is less stable than phenoxide as no resonance take place .Hence phenol is more acidic than water