solubility of halogen in organ

Down the group, the molecular size of halogen increases. This would lead to a stronger van der Waals' forces (instantaneous dipole - induced dipole attractions) between the halogen molecules.

However, as the increase of molecular size, the van der Waals' forces between the halogen molecules and the solvent molecules increase to a greater extent. Therefore, the solubility of halogens in organic solvent increases down the group.


kamyin1991's answer is incorrect.

Firstly, down the group, the van der Waals' forces (instantaneous dipole - induced dipole attractions) between the halogen molecules would increase, but NOT decrease.

Secondly, "Like-dissolve-like" principal can only explain that halogens dissolve in organic solvents, but cannot explain their difference in solubility. This is because all the halogens are non-polar, i.e. their polarities are the same.

Since both of organic solvent and halogen molecules are non-polar,there are only instantaneous dipole-induced dipole attractions beteen them.
When the size of halogen molecules increase,their instantaneous dipole-induced dipole attractions decreases,then by Like dissolve like principle, the total sum of attractions between the halogen molecules are smaller, then it is easier for the larger size halogen to dissolve in organic solvent.