In SF6, which intermolecular force(s) is/are present? Dispersion, dipole-dipole and hydrogen bonding forces are present. Only dispersion forces are present. Only dispersion and dipole-dipole forces are present. Only hydrogen bonding forces are present. Only dipole-dipole and hydrogen bonding forces are present.
The Correct Answer and Explanation is:
Correct Answer: Only dispersion forces are present.
Explanation:
Sulfur hexafluoride (SF₆) is a nonpolar molecule that contains sulfur (S) at the center and six fluorine (F) atoms symmetrically arranged around it in an octahedral geometry. This symmetric shape is the key to understanding the types of intermolecular forces acting between SF₆ molecules.
Despite fluorine being a highly electronegative atom and each S–F bond being polar, the molecular geometry causes all the individual bond dipoles to cancel each other out. As a result, SF₆ has no permanent dipole moment and is considered a nonpolar molecule overall.
Intermolecular forces are the forces that exist between molecules, and they vary depending on the polarity and structure of the molecule. There are three common types:
- Dispersion forces (London dispersion forces): These are weak forces that arise due to temporary shifts in the electron cloud of a molecule, creating a temporary dipole. Dispersion forces are present in all molecules, regardless of whether they are polar or nonpolar. They are the only intermolecular forces acting in nonpolar molecules like SF₆.
- Dipole-dipole forces: These occur between molecules that have permanent dipoles. Since SF₆ is nonpolar, these forces are not present.
- Hydrogen bonding: This is a special type of dipole-dipole attraction that occurs only when hydrogen is directly bonded to nitrogen, oxygen, or fluorine. SF₆ does not have any hydrogen atoms, so hydrogen bonding is not possible.
Therefore, the only intermolecular force present in SF₆ is dispersion forces, which are sufficient to hold SF₆ molecules together in the liquid or solid state under appropriate conditions.
