In each pair, which compound has the higher boiling point

Question

A. 1-butanol or butylamine

B. trimethylamine or propylamine

C. butylamine or diethylamine

D. butane or propylamine

Answer 1

This question is asking you to assess the factors that affect volatility.  The dominant effects are intermolecular forces that attract the molecules together such as hydrogen bonding, dipole moment; and molecular weight.

A)  Alcohols hydrogen bond, which is stronger than the dipole effect in butyl amine

B) TMA has symmetry and is a tertiary amine with a lower dipole moment than propyl amine, which is primary.

C) butylamine is primary (stronger dipole) than diethyl (secondary)

D) Butane (alkane, weak dipole) vs. propylamine (strong dipole)