Question

For phenol, which of the following statements is correct?
(A) It is insoluble in water
(B) It has higher boiling point than toluene
(C) It does not shows acidic properties
(D) It has lower melting point compared to aromatic hydrocarbons of comparable molecular weight

Answer 1

Hint : Boiling point of a compound is mainly determined by the intermolecular force of attraction. Phenol is aromatic alcoholic compounds in which a hydroxyl group is directly attached to the benzene ring.

Complete answer:
(A) like alcohols, phenol are soluble in water due to the formation of hydrogen bonding with water, but phenol are less soluble than alcohols due to the presence of a large hydrocarbon(benzene ring)part.
(B) Boiling point depends on strength of intermolecular forces or interactions. Boiling point of phenol is much higher than the corresponding aromatic hydrocarbon with the same molecular weight due to intermolecular hydrogen bonding.
(C) Phenols are weaker acidic in nature because a polar (O-H) bond is directly attached to aromatic carbon atoms. Phenols are weaker acid than acetic acid but more acidic than alcohol because resonance stability of phenoxide ions.
(D) Melting point of phenol is comparatively higher than other aromatic hydrocarbons because of strong intermolecular interaction. Phenol is a crystalline solid while corresponding hydrocarbons are liquid in nature.

So, option (B) is the correct option.

Note the hydroxyl group in alcohols is a polar group which can form hydrogen bonds with water and other polar groups. Presence of an electron withdrawing group increases the acidity of phenol by stabilising the phenoxide ion.