Question Detail
Question
Consider a small aliphatic 1° amine, 1° alcohol, ester, carboxylic acid, and amide, all of similar molecular weight. Which one is most likely to have the highest boiling point?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Amides can form very strong hydrogen bonds because the nitrogen can donate electrons to the carbonyl (more so than OH of a carboxylic acid), giving the oxygen considerable negative charge and enhancing H-bond acceptor capability. The general trend (highest to lowest boiling point) is: amides > carboxylic acids > alcohols > amines > aldehydes/ketones/esters.
Hint
Which compound forms the strongest hydrogen bonds?