Question

(I) 1,2-dihydroxybenzene
(II) 1,3-dihydroxybenzene
(III) 1,4-dihydroxybenzene
(IV) Hydroxybenzene.
The increasing order of boiling points of above mentioned alcohols is:

• A. I < II < III < IV
• B. I < II < IV < III
• C. IV < I < II < III
• D. IV < II < I < III.

Answer 1

The correct option is C IV < I < II < III

1, 4-dihydroxybenzene has intermolecular hydrogen bonding. So, it has the highest boiling point among all the given compounds.

1, 2-dihydroxybenzene has intramolecular hydrogen bonding. So, the boiling point will be less than that of 1, 4-dihydroxybenzene.

1, 3-dihydroxybenzene shows partial intermolecular and intramolecular hydrogen bonding. So, it has more boiling point than 1, 2-dihydroxybenzene and less than 1, 2-dihydroxybenzene. Hydroxybenzene does not have any hydrogen bonding, so it's boiling point is least among the three.

So the correct order is: (III)>(II)>(I)>(IV)