(i) Ethanol undergo intermolecular hydrogen bonding due to the presence of a hydrogen attached to oxygen atom .
As a result , ethanol exists as associated molecules and hence it has higher boiling point than ethoxy ethane which does not from hydrogen bonds .
(ii) Phenol is stronger and than ethanol because the phenoxide is stabilized by resonance but ethoxide ion is not , Moreover , ethoxide ion is distabilizied by $+I$ effect of ethyl group .
(iii) Due to I effect or R effect of $NO_2$ group , the resulting phenolate con is more stable than phenoxide ion.
Therefore O-and P -nitrophenols are more acidic than phenol
(iv) Phenol is a weaker acid than carbonic acid $(H_2CO_3)$ and hence does not liberate $CO_2$ from sodium bicarbonate .