Van der Waals' Forces and Hydrogen Bonding

[Priyadarshini]

Induced dipoles result in Van der Waals' forces and permanent dipoles in hydrogen bonds, right? But how do you know is a compound has formed hydrogen bonds or Van der Waals' forces? For example, HF forms hydrogen bonds while HCl forms Van der Waals' forces and not hydrogen bonds. But in HCl, H is delta positive and Cl is delta negative, so shouldn't it form hydrogen bonds? But then when do Van der Waals' forces form?
Thanks.

 

[mfb]

Those categories don't have a sharp dividing line. Some bonds are very van-der-Waals-like, some are very hydrogen-bond-like, some are somewhere in between.

 

[Priyadarshini]

Those categories don't have a sharp dividing line. Some bonds are very van-der-Waals-like, some are very hydrogen-bond-like, some are somewhere in between.

Oh, thanks!