Arrange the following compounds in order of decreasing boiling point, putting the compound with the highest boiling point first.

Question

Quizplus · Accepted Answer

The boiling point of a compound is primarily determined by two factors: the strength of the intermolecular forces and the size of the molecule. In this case, all three compounds are polar and can form hydrogen bonds, which are the strongest intermolecular forces. However, as the size of the molecule increases, the boiling point also increases because there are more electrons that can participate in London dispersion forces.

Compound I is the smallest and has the fewest electrons, so it has the weakest London dispersion forces. Compound II is larger than I and has more electrons, so it has stronger London dispersion forces. Compound III is the largest and has the most electrons, so it has the strongest London dispersion forces.

Therefore, the correct order of decreasing boiling points is III > I > II, which corresponds to choice C.

Arrange the Following Compounds in Order of Decreasing Boiling