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

Options

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. Propan-1-ol, butan-1-ol, butan-2-ol, pentan-1-ol

Answer

A

Explanation

Boiling point increases with increase in the number of carbon atoms because of increase in molecular mass. So, the boiling point of pentan-1-ol is more than that of all other given compounds. Further, among isomeric alcohols, 1° alcohols have higher boiling points than 2°alcohols because of higher surface area in 1° alcohols. Therefore, boiling point increase in the order
Propan-1-ol < butan-2-ol < butan-1-ol < pentan-1-ol.