The document discusses which pairs of compounds are expected to have unexpectedly low or high boiling temperatures. It analyzes four pairs - n-butane/2-methylpentane, acetone/dimethylamine, water/n-butane, and acetonitrile/benzene - based on the number of carbons and whether attractions like hydrogen bonding, polarity differences, or ionic interactions exist between the compounds. It determines that water and n-butane would have the lowest boiling point due to hydrogen bonding being the only interaction, while n-butane and 2-methylpentane would have the highest since there is no attraction between the nonpolar compounds.