Question

If a molecule $M{X}_3$ has zero dipole moment, the $\sigma$ - bonding orbitals used by M (atomic number < 21) is:

• A. pure $p$
• B. $sp$ - hybridized
• C. $s{p}^2$ - hybridized
• D. $s{p}^3$ - hybridized

Answer 1

Answer: (C)

$s{p}^2$ - hybridized

Since, the molecule $M{X}_3$ has zero dipole moment, the $\sigma$ - bonding orbitals used by M (atomic number $<21$) are $s{p}^2$ - hybridized. In this case, planar triangular geometry results in the cancellation of the dipole moments of individual $M-X$ bonds.

Hence, the overall molecule has zero dipole moment.