Question

What atomic or hybrid orbital on `C` makes up the sigma bond between `C` and `Cl` in carbon tetrachloride, `C Cl_4`?

Answer 1

The hybrid `sp^3` orbital

Explanation:

Carbon has four valance orbitals 1 s and 3 p s
In the ground state the electron configuration is `1s^2 2s^2 2p^2`

In the ground state Carbon can only form 2 bonds as in Carbon monoxide. `CO` To form 4 bonds as in Carbon tetrachloride `C Cll_4` Carbon has to blend all four orbitals the 1 s and 3 p s. This forms four equal `sp^3` tetrahedral orbitals. Each of the Cl atoms forms a sigma bond with one of these four equal hybridized orbitals.