Test: Intermolecular Forces - ACT MCQ

A Dutch scientist named Johannes van der Waals found out the reason for real gas behavior’s deviation from ideal gas behavior. And he said that those forces which were named van der Waals were responsible.

The interaction energy between two atoms or molecules experiencing dispersion or London forces is inversely proportional to the sixth power of the distance between those molecules when found, experimentally.

Dipole-Dipole interactions occur between molecules having permanent dipoles. And also the ends of dipoles posses partial charge which represented by a Greek letter δ. In an HCl molecule, the same type of interactions occur.

Dipole-induced dipole interactions occur between a molecule of permanent dipole and molecule lacking permanent dipole. The dipole gets induced to the other molecule in this particular interaction.

When two molecules come closer, the electron clouds between them they repel. This is the reason why solids and liquids cannot be easily compressed. As the distance between molecules decreases, the repulsive forces become much stronger.

Intermolecular means between molecules and intramolecular means within in molecule. Both attractive and repulsive forces include intermolecular forces. Therefore, the forces of attraction and repulsion between interacting molecules are known as Intermolecular forces.

Electrically symmetrical atoms and non-polar molecules having zero dipole movement due to their electron distribution may sometimes develop a momentary dipole also known as London force or the Dispersion forces.

Dipole-Dipole forces are stronger than London forces and weaker than ion-interactions. As only the partial charges are involved. London forces have no charges, and ion-ion forces have full charges.

The energy between two polar molecules which are stationary, is inversely proportional to the cube of the distance between the molecules, in the case of dipole-dipole intercations. This interaction is stronger than the London forces.

As per the above statement, substance properties and structure is determined as per the hydrogen bond present in them, but in a methane molecule, there is no hydrogen bond. So it may not be an example.