Question

Identify the correct order of boiling points of the following compounds.
$C{H}_{3}C{H}_{2}C{H}_{2}C{H}_{2}OH,C{H}_{3}C{H}_{2}C{H}_{2}CHO,C{H}_{3}C{H}_{2}C{H}_{2}COOH$
(A) (B) (C)

• A. (A) > (B) > (C)
• B. (C) > (A) > (B)
• C. (A) > (C) > (B)
• D. (C) > (B) > (A)

Answer 1

The correct option is B (C) > (A) > (B)

Acid (C) forms dimer due to intramolecular H-bonding. Alcohol (A) forms intermolecular H-bonding. H-bonding in (C) is stronger than in (A). Aldehyde (B) has dipole-dipole-dipole interaction. So the order of boiling points is: (C) > (A) > (B).