What are Van der Waals forces?!

Somebody has said that they are the sum of the attractive and repulsive forces, yet elsewhere I've heard that they are the same as instantaneous dipole-induced dipole bonds?

Thanks in advance

Reply 1

SaFa1237

Van der Waals forces include all attractive and repulsive forces between molecules. Except those forces which are due to covalent bonds or electrostatic interaction of ions. This includes instantaneous dipole-induced dipole. :smile:

Reply 2

ChemistBoy

Original post by SaFa1237

I believe that permanent dipole-dipole interactions such as hydrogen bonds are also excluded from the definition of Van der Waal's forces.

Reply 3

fruitaay95

Original post by gingernat

Somebody has said that they are the sum of the attractive and repulsive forces, yet elsewhere I've heard that they are the same as instantaneous dipole-induced dipole bonds?

Thanks in advance

They're intermolecular forces
How theyre formed: movement of electrons causes an instantaneous dipole
This dipole induces neighbouring dipoles
They all gain small forces of attraction
Van der waals

Posted from TSR Mobile

Reply 4

Plantagenet Crown

Original post by gingernat

Somebody has said that they are the sum of the attractive and repulsive forces, yet elsewhere I've heard that they are the same as instantaneous dipole-induced dipole bonds?

Thanks in advance

What Sa-Fa and Chemist Boy said. Van der Waals are also known as London forces

Reply 5

Muppet Science

What people have said above but note that they are very weak IMFs.

Reply 6

EierVonSatan

http://goldbook.iupac.org/V06597.html

The confusion comes from A-level texts/exams that use VdW forces to mean only instantaneous dipole-induced dipoles. Not overly helpful, really.