Dipole-Dipole vs London

[Amina Durrani 3G]

What’s the difference between Dipole-Dipole and London Forces and what’s an example of each?

[Trinity Vu 1D]

Dipole-dipole forces is an interaction between two polar covalent molecules such as HF. London dispersion forces are temporary induced dipole interactions that happen between non polar covalent molecules as the electron distribution fluctuates leaving one side of the molecule with more electrons and thus more negative than the other at an instant in time. An example of this would be C5H12

[Qilan Li 4I]

Dipole-dipole interactions occur when the positively charged part of a molecule interacts with the negatively charged part of another molecule. Induced dipole-induced dipole or London dispersion forces exist between all types of molecules (polar or nonpolar). Electrons constantly move so an atom or molecule can develop a temporary (instantaneous) dipole when its electrons are distributed unevenly around the nucleus (kinda like electrons clump together on one side). A second atom or molecule then can be attracted to the appearance of the dipole in the first atom or molecule.

[Rebekah Alfred 1J]

Examples of Dipole-Dipole Forces:

[RobertXu_2J]

London dispersion forces occur in all molecules. It refers to how, when electrons are moving randomly around the nucleus, there will always be an ebb and flow in how negatively/positively charged a particular region of that atom is. These slight imbalances that occur attract each other, so all atoms always have london dispersion forces acting between them. Dipole-Dipole on the other hand, refers to when two atoms with a positive end and a negative end, are attracted to each other.