Types of intermolecular forces

Intermolecular forces are those responsible for keeping molecules together in the formation of different compounds, they are classified as:
Dipole-induced force: it is caused by the accumulation of electrons in a certain region of the molecule.
The intermolecular interactions present in nonpolar molecules are dipole-induced, but they do not occur all the time, the distribution of electrons in the electrosphere of these molecules is uniform. However, at some point there is an accumulation of charges δ + and δ - (poles) at the ends, this is where the forces induced dipoles appear, and as the name implies, they induce neighboring molecules to also enter into imbalance.
See examples of nonpolar compounds whose molecules interact through dipole-induced forces:
Cl₂, CO₂, CH₄, H₂, O₂

Dipole-dipole forces: intermolecular force present in polar compounds.
δ + δ- δ + δ- δ + δ-
H? Br H? Br H? br

Note that in hydrobromic acid (HBr) molecules there are poles δ + and δ-, they are responsible for this molecule being polar.

Examples of polar compounds in which dipole-dipole interaction occurs:
H₂S, CO, SO₂, HCl

Hydrogen bonds: This is the strongest interaction that occurs between molecules, compared to the much more enhanced dipole-dipole strength. This bond occurs between molecules that contain hydrogen atoms bonded to nitrogen atoms, fluorine, oxygen, that is, very electronegative elements, so the δ + and δ- poles are more accented.
The water molecule is a classic example of hydrogen bonds, where H atoms bond tightly with the H atoms of other molecules to form the H chain.₂0.
See which intermolecular force is more intense through the figure below:

The arrow indicates the ascending order of interaction intensity.

Do not stop now... There's more after the advertising ;)

By Líria Alves
Graduated in Chemistry
Brazil School Team

See more:
Intermolecular forces and solubility
Experiment that allows testing which substance is polar and non-polar.

General chemistry - Chemistry - Brazil School

Would you like to reference this text in a school or academic work? Look:

FOGAÇA, Jennifer Rocha Vargas. "Types of intermolecular forces"; Brazil School. Available in: https://brasilescola.uol.com.br/quimica/tipos-forcas-intermoleculares.htm. Accessed on June 27, 2021.