First, we have to distinguish between intramolecular and intermolecular forces.

Intramolecular forces are bonds between atoms within a molecule.

Here, for example, we have ionic bonds and covalent sigma bonds.

In general, these intramolecular bonds are very strong compared to intramolecular interactions.

And their role in chemical reactions is very clear, I think.

They enable the formation of new molecules.

We also have intramolecular forces, which are bonds between molecules.

They are generally weaker than the intramolecular forces.

In this category we have the very well known hydrogen-bond bonds.

We also have halogen bonds and ion dipole-change effects.

Here we have the well known van der Waals forces.

This includes dipole-dipole-change effects and London forces.

These two last ones here are actually very weak.

And in chemical reactions, these intermolecular forces are very important.

Especially important for reactions that take place in a solvent.

These forces or change effects determine, for example, the solubility of the educts

or the transverse states

and also the products in the solubility.

And as we have already seen,

this solubility has a very big influence

of the reaction-speed.