Is the SF5 ion polar or non-polar? You must give an explanation for your answer in order to receive credit.
The correct answer and explanation is:
The SF₅⁻ ion is polar due to its molecular geometry and the electronegativity differences between sulfur and fluorine atoms.
Explanation (300 words):
The SF₅⁻ ion consists of a central sulfur (S) atom bonded to five fluorine (F) atoms. To determine whether this ion is polar or nonpolar, we must analyze its molecular geometry, electronegativity, and dipole moment.
- Molecular Geometry:
The sulfur atom in SF₅⁻ follows the AX₅E molecular structure (where A is the central atom, X is a bonded atom, and E represents lone pairs). According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, this arrangement results in a square pyramidal geometry. This shape arises because sulfur has five bonding pairs and one lone pair of electrons. The presence of a lone pair affects symmetry by distorting the molecular structure. - Electronegativity Difference:
Fluorine is the most electronegative element (3.98) compared to sulfur (2.58). The S–F bonds are highly polar covalent, meaning fluorine pulls electron density towards itself. Since the fluorine atoms are not symmetrically arranged due to the lone pair, their individual dipole moments do not cancel out. - Dipole Moment:
If SF₅⁻ had a perfect symmetrical shape (like a trigonal bipyramidal SF₅ molecule), the dipole moments might cancel. However, due to its asymmetrical square pyramidal shape, there is a net dipole moment, making the molecule polar.
Conclusion:
Since SF₅⁻ has an asymmetrical shape and polar bonds, the molecule has a net dipole moment and is therefore polar.
Now, I will generate an image of the SF₅⁻ molecular structure to visualize its geometry.