# Why does HI have a higher boiling point than HBr, and HCl?

Given its polarizability, the diffuse electron cloud of the $H I$ molecule allows more effective (i.e. more attractive) intermolecular interaction. Given this enhanced intermolecular interaction, $H I$ should have a higher $\text{boiling point/melting point}$ than $H C l$. You will have to look up the physical constants, here is a start.
But hang on, $H F$, has a boiling point of $19.5$ ""^@C, which is the highest of the hydrogen halides. Doesn't this contradict what I have said? What's going on?