Question

Out of the following hybrid orbitals, the one which forms the bond at angle \[120^\circ \] is
A) \[{d^2}s{p^3}\]
B) \[s{p^3}\]
C) \[s{p^2}\]
D) \[sp\]

Answer 1

Hint: The hybridization of a molecule decides its bond angle. Here, we will understand the bond angles shown by \[s{p^3}\], \[s{p^2}\] , \[sp\] and \[{d^2}s{p^3}\]hybridized molecule. The bond angle also determines molecular shape.

Complete step by step solution:Let’s first understand what hybridization is. This is the process of intermixing of orbitals to give a new group of orbitals possessing different shapes and energies.
Now, we will understand the bond angles of all the hybridized molecules.
The \[{d^2}s{p^3}\]hybridization means six electron groups surround the central atom. The surrounding groups are atoms bonded to the central atom and the count of lone pairs. So, its bond angle is \[90^\circ \]. For example, \[{\rm{S}}{{\rm{F}}_{\rm{6}}}\] is \[{d^2}s{p^3}\]hybridized.
The \[s{p^3}\] hybridized molecule has four electron groups surrounding the central atom. So, the bond angle in this hybridized molecule is \[109^\circ 28'\] . For example, \[{\rm{C}}{{\rm{H}}_{\rm{4}}}\] is \[s{p^3}\] hybridized.
The \[s{p^2}\] hybridized molecule has three electron groups surrounding the central atom. So, the bond angle in this hybridized molecule is \[120^\circ \] . For example, \[{\rm{B}}{{\rm{F}}_{\rm{4}}}\] is \[s{p^3}\] hybridized.
An \[sp\] hybridize molecule has two electron groups surrounding the central atom. So, the bond angle in an sp hybridized molecule is \[180^\circ \] . The carbon dioxide molecule is an \[sp\] hybridized molecule.

Therefore, option C is right.

Note: The hybridization also tells the geometry and shape of a molecule. If no lone pair is present, the \[s{p^3}\] hybridization denotes a tetrahedral molecule, the \[s{p^2}\] hybridization is for a trigonal planar and an \[sp\] hybridization denotes a linear molecule and the \[{d^2}s{p^3}\]hybridization is for an octahedral molecule. But, the presence of lone pairs alters the shapes of molecules.