Give reasons for the following:
(i) Phenol is more acidic than methanol.
(ii) The C-O-H bond angle in alcohols is slightly less than the tetrahedral angle (109°28').
(iii) (CH3)3C-O-CH3 on reaction with HI gives (CH3)3C-I and CH3-OH as the main products and not (CH3)3C-OH and CH3-I.

(1) Phenoxide ion is more stabilized than -CH3O- ion through resonance. Thus, phenol is more acidic than methanol.
(2) Due to extensive intermolecular H-bonding, the -C-O-H bond angle in alcohol is slightly less than the tetrahedral angle. H-bond thrusts the angle slightly.
(3) Since (CH3)3C+ is more stabilized through the +I effect of three methyl groups, thus (CH3)3C-I and CH3OH are formed on treatment of HI with -(CH3)3-CO-CH3. Me3C-O-Me → Me3C+ + MeO- + HI → Me3C-I + MeOH