The intermolecular forces between molecules are caused by the attraction between the positive and negative charges in the molecules.
Nitrogen (N2) is a nonpolar molecule, which means that the electrons are evenly distributed around the molecule and there is no net positive or negative charge.
On the other hand, carbon monoxide (CO) is a polar molecule, which means that the electrons are not evenly distributed around the molecule and there is a net positive charge on the carbon atom and a net negative charge on the oxygen atom.
The polar nature of CO creates stronger intermolecular forces than the nonpolar nature of N2. The stronger intermolecular forces between CO molecules cause them to stick together more tightly than N2 molecules, which means that more energy is required to break the intermolecular forces and boil CO than N2. Therefore, CO has a higher boiling point than N2.
Boiling point is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid is directly related to the strength of the intermolecular forces between the molecules of the liquid. stronger the intermolecular forces, the higher the boiling point.
In summary, N2 has a lower boiling point than CO because the intermolecular forces between N2 molecules are weaker than the intermolecular forces between CO molecules.
