Question

The type of hybridization in \[{\text{S}}{{\text{F}}_6}\] molecule is:
A. \[s{p^3}d\]
B. \[ds{p^3}\]
C. \[s{p^3}{d^2}\]
D. \[{d^2}s{p^3}\]

Answer 1

Hint: First let us determine the valence shell electronic configuration of the central atom. Then determine the steric number. Then determine the hybridization and the geometry of the molecule.

Complete answer:
The chemical formula \[{\text{S}}{{\text{F}}_6}\] represents the compound sulphur hexafluoride. The central atom in \[{\text{S}}{{\text{F}}_6}\] molecule is a sulphur atom.

The atomic number of sulphur is 16. The electronic configuration of sulphur is \[\left[ {{\text{Ne}}} \right]{\text{ 3}}{{\text{s}}^2}{\text{3}}{{\text{p}}^4}\] . The sulphur atom has six valence electrons. A sulphur-fluorine bond is formed when one electron of sulphur is shared with one electron of fluorine.
 In sulphur hexafluoride molecules, the sulphur atom forms six bonds with six fluorine atoms. Thus, all the six valence electrons of the central sulphur atoms are consumed in formation of six sulphur-fluorine bonds. Thus, the number of lone pairs of electrons on the sulphur atom is zero. Thus, the central sulphur atom has six bond pairs of electrons and zero lone pairs of electrons. The steric number of sulphur is six.

The steric number of six is associated with \[s{p^3}{d^2}\] hybridization. One s, two d and three p atomic orbitals of central sulphur atom undergo \[s{p^3}{d^2}\] hybridization to form six degenerate hybrid orbitals. These six degenerate hybrid orbitals overlap with atomic orbitals of six fluorine atoms to form six sulphur-fluorine sigma covalent bonds.

The steric number of six is associated with octahedral molecular geometry. Since the number of lone pairs of electrons is zero, the molecular geometry and the electron pair geometry are the same as octahedral. Since the type of hybridization in the sulfur hexafluoride molecule is \[s{p^3}{d^2}\].

Hence, the correct answer is the option (C).

Note: The steric number gives the total number of bond pairs and lone pairs of electrons present around the central atom in a compound. For example, in the sulphur hexafluoride molecule, six bond pairs and zero lone pairs of electrons are present. Hence, the steric number is \[6 + 0 = 6\].