Problems and exercisesPhysical Properties

1. Order by boiling point

Arrange in order of increasing boiling point: hexane, 2,2-dimethylbutane, pentane and butane.

2. Isomers and contact surface

The C₅H₁₂ isomers boil at 36.1 °C (pentane), 27.8 °C (2-methylbutane) and 9.5 °C (2,2-dimethylpropane). Explain this trend.

3. Which intermolecular forces?

State the most important intermolecular force between the molecules of each substance:

1. Octane
2. Chloromethane, CH₃Cl
3. Methanol, CH₃OH
4. Water

4. Alkanes and water

Why does an alkane such as hexane not mix with water and float on it?

5. True or false?

1. When an alkane boils, its C–C bonds break.
2. Alkanes with 1 to 4 carbons are gases at room temperature.
3. No alkane reaches the density of water.