Arrange water, ethanol and phenol in increasing order of acidity and give reason for your answer.

Increasing order of acidity is: Ethanol < water < phenol

After deprotonation, in case of phenol, phenoxide ion is formed and gets stabilized by the resonance. Thus, phenol is most acidic among the three given compounds.

The ethoxide ion produced after the removal of proton from ethanol gets destabilized by the positive inductive effect of the ethyl group. Therefore, ethanol is less acidic than phenol. The electron releasing group of ethanol increases the electron density on oxygen and hence, the removal of proton from ethanol is difficult. Water is better proton donor than ethanol. Thus, ethanol is weaker acid than water.