The molecular geometry of the SF, molecule is linear. d. tetrahedral. b. bent. c. octahedral. C trigonal planar.
The Correct Answer and Explanation is :
The molecular geometry of sulfur difluoride (SF₂) is bent. This configuration arises due to the presence of two bonding pairs and two lone pairs of electrons on the central sulfur atom. According to the Valence Shell Electron Pair Repulsion (VSEPR) theory, electron pairs around a central atom arrange themselves to minimize repulsion, leading to specific molecular shapes.
Lewis Structure and Electron Arrangement
To understand SF₂’s molecular geometry, we first examine its Lewis structure. Sulfur (S) has six valence electrons, and each fluorine (F) atom has seven valence electrons, totaling 20 valence electrons for the SF₂ molecule. In the Lewis structure, sulfur is the central atom bonded to two fluorine atoms, with each bond accounting for two electrons, totaling four bonding electrons. The remaining 16 electrons are distributed as lone pairs: each fluorine atom receives six electrons (three lone pairs) to complete their octets, and the sulfur atom retains the remaining four electrons as two lone pairs.
VSEPR Theory and Molecular Geometry
The VSEPR theory predicts molecular shapes based on electron pair repulsions. For SF₂, the sulfur atom has four regions of electron density: two bonding pairs (S–F bonds) and two lone pairs. This corresponds to a steric number of 4, which typically leads to a tetrahedral electron geometry. However, the molecular geometry considers only the positions of the atoms, not the lone pairs. The lone pairs occupy more space than bonding pairs, causing the bonding pairs to be pushed closer together. As a result, the molecule adopts a bent shape to minimize electron pair repulsion.
Bond Angle and Hybridization
In an ideal tetrahedral arrangement, bond angles are approximately 109.5°. However, in SF₂, the presence of lone pairs reduces the bond angle due to increased electron repulsion. Empirical data indicates that the F–S–F bond angle in SF₂ is about 98°, reflecting the influence of the lone pairs in compressing the bond angle. Regarding hybridization, the sulfur atom in SF₂ undergoes sp³ hybridization, forming four sp³ hybrid orbitals: two for bonding with fluorine atoms and two occupied by lone pairs.
Polarity
The bent geometry of SF₂ results in an asymmetric distribution of electron density. Coupled with the significant electronegativity difference between sulfur and fluorine atoms, this asymmetry leads to a polar molecule with a net dipole moment.
In summary, the bent molecular geometry of SF₂ is a consequence of the two bonding pairs and two lone pairs of electrons around the central sulfur atom, as explained by VSEPR theory. This arrangement leads to a bond angle of approximately 98°, sp³ hybridization, and a polar nature for the molecule.