# Which has a lower boiling point, Ozone or CO2? Why?

Ozone is a bent molecule, and therefore, Ozone is a polar molecule. Polar molecules have dipole-dipole intermolecular forces. CO2 is a linear molecule, and therefore, CO2 is a nonpolar molecule. Nonpolar molecules have london dispersion intermolecular forces.

Having dipole-dipole intermolecular forces means you have greater intermolecular forces than London dispersion forces, and therefore means that you have a higher boiling point. Therefore, Ozone should have a higher boiling point than CO2.

However, after looking at multiple sources across the internet, Ozone has a lower boiling point than CO2. Could someone provide an explanation as to why this is true?

• CO2 does not melt and hence boil at normal pressure, but sublimes instead. A better comparison would be to find ozone's melting or boiling point at a pressure where CO2 melts or boils. Alternatively consider comparing the triple points. Jan 31 '20 at 9:10

For comparing the boiling points, we need to see the extent of intermolecular attraction as a measure for the same. Due to the difference in electronegativities between $$\ce{C}$$ and $$\ce{O}$$, $$\ce{CO2}$$ ends up having more partial charges on its constituent atoms as compared to ozone. Hence, the boiling point of carbon dioxide is more than ozone