Dimethylamine, (CH₃)₂NH, has a molecular weight of 45 and a boiling point of 7.4 °C. Trimethylamine, (CH₃)₃N, has a higher molecular weight (59) but a lower boiling point (3.5 °C). Explain this apparent discrepancy.

Rank the following substituted anilines from most basic to least basic:

Rank each set of compounds in order of increasing boiling points.

(a) triethylamine, di-n-propylamine, n-propyl ether

(b) ethanol, dimethylamine, dimethyl ether

(c) diethylamine, diisopropylamine, trimethylamine

In each pair of compounds, select the stronger base, and explain your choice.

(a) HOCH₂CH₂NH₂ or CH₃CH₂NH₂

(b) PhNH₂ or PhCH₂NH₂

Within each structure, rank the indicated nitrogens by increasing basicity.

(a)

(b)

Rank each set of compounds in order of increasing basicity.

(d) pyrrole, imidazole, 3-nitropyrrole

Rank each set of compounds in order of increasing basicity.

(c) aniline, pyrrole, pyridine, piperidine

Rank each set of compounds in order of increasing basicity.

(b) aniline, p-methylaniline, p-nitroaniline