Question

Arrange the following compounds in the increasing order of their boiling points:
Butane, 1-Bromobutane, 1-Iodobutane, 1-Chlorobutane

Hint:

In halogen-substituted alkanes, boiling points increase as the size of the halogen increases due to stronger intermolecular forces.

Answer 1

The increasing order of boiling points is:
Butane < 1-Chlorobutane < 1-Bromobutane <1-Iodobutane.
- The boiling point increases as the size of the halogen increases because larger atoms form stronger van der Waals forces, which increase the boiling point.
- Iodine, being the largest halogen, results in the highest boiling point, followed by bromine, chlorine, and then butane, which lacks halogen atoms.


Step 1: The halogen's atomic size increases in the order Cl < Br < I, and this correlates with increasing boiling points.


Step 2: Butane has no halogen, so it has the lowest boiling point, followed by chlorobutane, bromobutane, and iodobutane.