Which type of intermolecular force is primarily responsible for the sublimation of dry ice (solid CO_2) at atmospheric pressure?

• A. Dipole-dipole interactions
• B. Hydrogen bonding
• C. London dispersion forces
• D. Ionic bonding

Answer: (C)

Verified step by step guidance

1. Identify the nature of the molecule involved: CO_2 is a linear molecule with two polar C=O bonds arranged symmetrically, making the overall molecule nonpolar.
2. Recall that nonpolar molecules do not have permanent dipole moments, so dipole-dipole interactions and hydrogen bonding are not significant forces in this case.
3. Understand that dry ice (solid CO_2) is held together in the solid phase primarily by weak intermolecular forces rather than ionic or covalent bonds between molecules.
4. Recognize that London dispersion forces (also called induced dipole-induced dipole interactions) are the primary intermolecular forces present in nonpolar molecules like CO_2.
5. Conclude that the sublimation of dry ice at atmospheric pressure occurs because London dispersion forces are relatively weak, allowing CO_2 molecules to transition directly from solid to gas.