Hydrogen bonding and Van der Waals forces

[DentAK907]

---

Members do not see this ad.

Im not sure if I'm understanding this question correctly. I though that h-bonding is technically a type of van der waals force because it is just a specific type of dipole-dipole force. This Crack the DAT question says otherwise. If anyone could help me clarify this I would greatly appreciate it!

Thanks

Question is in attachment below:

 

[Likkriue]

Van der vals is based on size of the atom. Hydrogen bonds are not van der wals (London dispersion forces) and are much stronger.

 

[Socolaphile]

Intermolecular forces: (strongest) H-bond > Dipole-dipole > LDF/Van der Waals (weakest)
-H-bond: Hydrogen bonding with F, O, N.
-Dipole-dipole: H-Cl-----H-Cl, there's a dipole. Cl is partial negative and H is partial positive = dipole.
-LDF: all molecules have them, but nonpolar molecules ONLY has LDF.

To answer your question, H-bond is NOT LDF/Van der Waals. H-bond is one of the intermolecular forces. LDF/Van der Waals is another type of IMF.

 

[tommyngu]

Although H-Bonding can be understood as a specific type of Dipole-Dipole, it's not classified as a Van der Waals force as it's much stronger than the Van der Waals forces along with some other reasons that set it apart.
Van der Waals forces include Dipole-Dipole interactions and London Dispersion forces.
side note: some people use the term Van der Waals force to mean London Dispersion force. Although I've seen sources use the terms interchangeably, I'd avoid doing it.