Question

The increasing order of boiling points of the following compounds is :

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

Answer 1

Answer: (A)

Alter

Increasing order of boiling point is :



$\Rightarrow $ Show hydrogen bonding from $- O- H$ group only



$\Rightarrow $ Shows stronger hydrogen bonding from both sides of $-OH$ group as well as $-NO_2$ group.



$\Rightarrow $ Shows stronger hydrogen from both side of

-OH group as well as $- NH _{2}$ group.



$\Rightarrow $ Shows stronger hydrogen bonding from one side $-$ OH-group and another side of $- OCH _{3}$ group shows only dipole-dipole interaction.

$\Rightarrow $ Hence correct order of boiling point is:

$( I )<( IV )<( III )<( II )$