Statement-I: Stability of  RCH2O−>R2CHO−>R3CO−Statement-II: +I effect of alkyl gp increases, polarity of O-H bond increases in alcohols.

As the number of alkyl groups increases (+I groups) electron density on oxygen atom of alcohol increases, polarity of O-H bond decreases in alcohol. More over increase in the number of +I groups increases the accumulation of negative charge of oxygen atom in alkoxide ion (RO-) and thus decreases the stability. Stability of  RCH2O−>R2CHO−>R3CO−