Arrange the following compounds in increasing order of boiling point:

(A) n-C₄H₉OH

(B) n-C₄H₉NH₂

(C) n-C₄H₁₀

(D) C₂H₅NHC₂H₅

Boiling point depends mainly on intermolecular forces.

Let us compare the compounds:

• n-Butane (C): Only weak London dispersion forces are present.
• Diethylamine (D): Has dipole-dipole interactions and limited hydrogen bonding.
• n-Butylamine (B): Stronger hydrogen bonding than secondary amines.
• n-Butanol (A): Strong O-H hydrogen bonding, which is stronger than N-H hydrogen bonding.

Therefore:

n-Butane has the lowest boiling point.

Diethylamine has a higher boiling point than butane because of polar interactions.

n-Butylamine has stronger intermolecular hydrogen bonding and therefore boils at a higher temperature.

n-Butanol exhibits the strongest hydrogen bonding among the given compounds and thus has the highest boiling point.

Increasing order:

C < D < B < A

Final Answer

Option (1)

n-C₄H₁₀ < C₂H₅NHC₂H₅ < n-C₄H₉NH₂ < n-C₄H₉OH