(i) Ethanol undergoes intermolecular hydrogen bonding due to the presence of a hydrogen attached to oxygen atom. As a result, ethanol exist as associated molecules and hence it has higher boiling point than methoxy ethane which does not form hydrogen bonds.
(ii) Phenol is stronger acid than ethanol because the phenoxide ion left after the release of proton is stabilized by resonance but ethoxide ion is not. Moreover, ethoxide ion is destabilised by +I effect of ethyl group.
(iii) Due to –I effect or –R effect of –NO2 group, the resulting phenolate ion is more stable than phenoxide ion. Therefore o- and p--nitrophenols are more acidic than phenol