Solid carbon dioxide (dry ice) is used as a refrigerating agent because it readily changes directly from the solid into the vapor state at low temperature. What does this indicate the main intermolecular bonding / forces in CO2(s) to be?

Explanation

Option D is correct.The main intermolecular bonding forces in CO2(s) are London dispersion forces. London dispersion forces are the weakest type of intermolecular force. They occur between all molecules, but they are only significant when the molecules are large or have highly electronegative atoms. Carbon dioxide is a nonpolar molecule, so it does not have dipole-dipole forces or hydrogen bonding. However, the carbon dioxide molecules are polar because of the difference in electronegativity between carbon and oxygen. This difference in electronegativity creates a temporary dipole in each molecule, which can induce a dipole in neighboring molecules. The interaction between these induced dipoles is what creates London dispersion forces. The strength of London dispersion forces increases with the number of electrons in a molecule. Carbon dioxide has 12 valence electrons, which is relatively high for a nonpolar molecule. This means that the London dispersion forces in CO2(s) are relatively strong. The strong London dispersion forces in CO2(s) make it difficult for the molecules to move past each other. This is why solid carbon dioxide is a solid at room temperature. However, at low temperatures, the thermal energy of the molecules is not enough to overcome the London dispersion forces. As a result, the molecules can escape from the solid state and enter the vapor state.