Arrange the compounds in order of increasing boiling point temperature: O2, NO, N2

Answer 1

Since boiling point is a physical property, intermolecular forces will determine the answer. The substance with the strongest intermolecular forces will have the highest boiling point because the most energy will be required to separate liquid particles' attraction.

Intermolecular forces depend on structure. Oxygen and Nitrogen are both non polar molecules, so they have london dispersion forces (LDF). LDF are stronger for molecules of higher molar masses. Since O₂ has a higher molar mass than N₂ (32 and 28 g/mol, respectively), O₂ has a more polarizable electron cloud than N₂. This means that partial, temporary charge created in O₂ is of greater magnitude than that of N₂.

NO is a polar molecule. Polar molecules have dipole-dipole forces.

Dipole-dipole forces are stronger than London Dispersion forces, so NO has the highest boiling point. O₂ has stronger LDF than N₂, so O₂ has the second highest boiling point.

N₂ < O₂ < NO