What intermolecular forces exist between Cl2 molecules? – dipole-dipole forces – hydrogen bonding – London dispersion forces – none are correct – ion-dipole forces
The Correct Answer and Explanation is:
The correct answer is London dispersion forces.
Explanation:
The intermolecular forces present between chlorine molecules (Cl₂) are primarily London dispersion forces, also known as induced dipole-induced dipole forces. This is because Cl₂ molecules are nonpolar, and the only intermolecular forces that can occur between nonpolar molecules are London dispersion forces.
What are London dispersion forces?
London dispersion forces are weak forces that arise from the temporary fluctuations in the electron distribution within molecules. Even though Cl₂ is nonpolar overall, the electrons in a chlorine molecule are in constant motion. At any given moment, the electrons may be unevenly distributed, creating a temporary dipole. This temporary dipole can induce a corresponding dipole in a neighboring molecule, resulting in an attractive force between them. These forces are present in all molecules, but they are especially significant in nonpolar molecules.
Why not the other options?
- Dipole-dipole forces: These forces occur between polar molecules where there is a permanent dipole. Since Cl₂ is nonpolar, dipole-dipole interactions do not occur between Cl₂ molecules.
- Hydrogen bonding: Hydrogen bonding occurs when hydrogen is directly bonded to highly electronegative atoms like fluorine, oxygen, or nitrogen. Since Cl₂ molecules do not contain hydrogen bonded to these atoms, hydrogen bonding does not apply here.
- Ion-dipole forces: Ion-dipole forces occur between an ion and a polar molecule. Since Cl₂ is neither an ion nor polar, ion-dipole forces are not relevant in this case.
- None are correct: This option is incorrect because London dispersion forces do exist between Cl₂ molecules.
Thus, London dispersion forces are the only significant intermolecular force between Cl₂ molecules. These forces are relatively weak compared to other types of intermolecular forces like hydrogen bonding or ionic interactions.