Question

Arrange the following compounds in increasing order of boiling point.
Propan-$1-ol$, butan-$1-ol$, butan-$2-ol$, pentan-$1-ol$

• A. Propan$-1-ol$, butan$-2-ol$, butan$-1-ol$, pentan$-1-ol$
• B. Propan$-1 -ol$, butan$-1 -ol$, butan$-2-ol$, pentan$-1 -ol$
• C. Pentan$-1 -ol$, butan$-2-ol$, butan$-1 -ol$, propan$-1 -ol$
• D. Pentan$-1-ol$, butan$-1-ol$, butan$-2-ol$, propan$-1-ol$

Answer 1

Answer: (A)

The boiling point increases as the moleculer mass of the alcohol increases. Further, among isomeric alcohols, $1^0$ alcohols have higher boiling points than $2^0$ alcohols. Therefore the b.p.t increases in the order: propan-1-ol < butan-2-ol < butan-1-ol < pentan-1-ol.