Question

In carbon monoxide molecule,
A. `C` is `sp^(2)`-hybridized but `O` is `sp^(3)`-hybridized
B. `C` is `sp`-hybridized but `O` is `sp^(2)`-hybridized
C. Both `C` and `O` are `sp^(2)`-hybridized
D. Both `C` and `O` are `sp`-hybridized

Answer 1

Correct Answer - D

One `sp` hybrid each of `c` and `O` overlaps to form a `C-O, sigma` bond while the other `sp` hybrid orbital on each atom contains the lone pair of electrons. The two unhybridized `p` atomic orbitals of `C` and `O` overlap sideways to form `p_(pi)-p_(pi)` multiple bond. Thus, `CO` is a linear moleuclar with the following Lewis structure:
`:C=overset(..)(O):`
In this Lewis structure, `C` has `6` while `O` has `8 e^(-) s` in the valence shell. To complete the octet around `C`, the `O` atom donates one of its lone pair into the empty `2p_(z)` atomic orbital of `C` as shown in the following Lewis structure:
`:Coverset(larr)(=)O:` or `:overset(-)(C )-=overset(+)(O):`
Thus, the real structure of `CO` is best regarded as the hybrid of the following resonance structures: