Question

You are given three different compounds. Given these compounds you find the following information:

Hexane has boiling point of 69 degrees

2-methylpentane has boiling point of 62 degrees

2,2-dimethylbutane has boiling point of 48 degrees

Question: Why do these compounds have different boiling points if they are all alkanes with the same number of carbons?

Answer 1

Boiling point depends on the force of attraction betwen 2 molecule.
The force acting here is vander walls forces of attaction. It becomes smaller and smaller as molecule tends to attain spheriical shape.
As we are moving from Hexane to 2-methylpentane to 2,2-dimethylbutane , molecules are becoming spherical and hence van der walls forces of attraction is decreasing.
So, Hexane has maximum boiling point and 2,2-dimethylbutane has minimum

Answer 2

The boiling point depends on the force of attraction between two molecules. The force acting here is Vander wall's force of attraction. It becomes smaller and smaller as the molecule tends to attain a spherical shape. As we are moving from Hexane to 2-methylpentane to 2,2-dimethylbutane , molecules are becoming spherical and hence van der walls forces of attraction are decreasing. So, Hexane has a maximum boiling point and 2,2-dimethylbutane has a minimum