Question

What are some examples of trigonal `sp^2` hybrids?

Answer 1

Examples of `sp^2` trigonal planar molecules are `BCl_3`, `BF_3`, `CH_2O`, and `CO_3^(2-)`.

Explanation:

In order for an atom to be `sp^2` hybridized, its steric number, which tells you how many regions of electron density surround an atom, must be equal to 3.

Three regions of electron density `->` three hybrid orbitals.

In order for a molecule to have a trigonal planar molecular geometry, its central atom must be bonded to three atoms and have no lone pairs of electrons present.

In other words, all the three regions of electron density that surround the atom must be bonds to other atoms.

Boron trifluoride, `BF_3`, and boron trichloride, `BCl_3`, are excellent examples of `sp^2` trigonal planar molecular geometry.

In both cases, the central boron atom is bonded to three other atoms and has no lone pairs present.

Other examples are formaldehyde, `CH_2O`

and the carbonate ion, `CO_3^(2-)`