The boiling points of halogens increase with increase in molecular weight, it is because

The boiling point of alkyl halide increases with increase in the molecular weight because, the surface area and the magnitude of the vander waals forces increases. The decreasing order of the boiling points of alkyl halides is RI>RBr>RCl>RF. As the size of the halogen increases, the magnitude of vander waals forces increases and the boiling point increases