Question

Which molecule will undergo only London dispersion forces when interacting with other molecules of the same kind? a.HCl b.C2H5OH c.NH3 d.CH4

Answer 1

Answer:

CH4

Explanation:

London dispersion forces are a type of force acting between atoms and molecules that are normally electrically symmetric; that is, the electrons are symmetrically distributed with respect to the nucleus. They are part of the van der Waals forces(Wikipedia).  It is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. This force is sometimes called an induced dipole-induced dipole attraction(Chem Purdue).

If we consider HCl, C2H5OH  and NH3, we will discover that they all have polar bonds. Consequently, dipole - dipole interaction as well as hydrogen bonds exist between their molecules.

CH4 is nonpolar. Being a nonpolar molecule, the only possible intermolecular interaction forces between its molecules is the London dispersion forces.