Which member of the following pairs has the larger London dispersion forces?
SiH4 or GeH4?
We are being asked to determine which among SiH4 or GeH4 has a larger London dispersion force.
Recall: The London dispersion force is the weakest intermolecular force.
It is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.
The dispersion force increases with increasing molar mass because molecules or atoms of a higher molar mass generally have more electrons dispersed over a greater volume.