Question

Arrangement of following compounds based on their boiling points in the increasing order : $n-butane, 1-butanol, ethoxyethane \,and \,1-propanol$ will be

• A. $1-propanol > n-butane > ethoxyethane > 1-butanol$
• B. $n-butane < ethoxyethane < 1-propanol < 1-butanol$
• C. $n-butane < 1-propanol < ethoxyethane < 1-butanol$
• D. $1-propanol < n-butane < ethoxyethane < 1-butanol$

Answer 1

Answer: (B)

Boiling point increases with increase in molecular mass so, 1-butanol has higher boiling point than 1-propanol.Unlike alcohols, ethers do not form hydrogen bonds thus, they have lower boiling points than the corresponding alcohols. Due to weak dipole-dipole interactions, the boiling points of lower ethers are only slightly higher than those of the n-alkanes having comparable molecular masses.Thus, the increasing order of boiling points is n-butane < ethoxyethane < 1-propanol < 1-butanol.