# Which of these molecules has dispersion forces as its strongest intermolecular force? "Br"_2, "H"_2"S", "HCl", "CO"

Sep 10, 2017

Only the molecule with no other intermolecular force would have dispersion forces as its strongest intermolecular force.

By the way, trick question here: which molecule has the highest boiling point?

And since only ${\text{Br}}_{2}$ is nonpolar, it is the only one with only dispersion forces.

• $\text{H"_2"S}$ is polar, and has dipole-dipole interactions as its dominant intermolecular force.
• $\text{HCl}$ is polar, and has dipole-dipole interactions as its dominant intermolecular force.
• $\text{CO}$ is polar, and has dipole-dipole interactions as its dominant intermolecular force.

As examples, the $\text{C}$ end of $\text{CO}$ is partially negative (not $\text{O}$!), and the $\text{Cl}$ end of $\text{HCl}$ is partially negative. Which end of $\text{H"_2"S}$ is partially positive?