Draw the Lewis structure of CO, Which of the description is correet?
A. There are 14 valence electrons in the Lewis structure of this covalent compound
B. There are four valence electron shared in the Lewis structure.
C. Carbon is the central atom because carbon is more electronegative than oxygen.
D. This is a bent and polar molecule
E. This is a linear and nonpolar molecule.
The Correct Answer and Explanation is:
Correct Answer: A. There are 14 valence electrons in the Lewis structure of this covalent compound.
Explanation (Approx. 300 Words):
The compound CO (carbon monoxide) consists of one carbon atom and one oxygen atom. To draw its Lewis structure, we begin by counting the total number of valence electrons.
- Carbon (C) has 4 valence electrons.
- Oxygen (O) has 6 valence electrons.
- Total valence electrons = 4 (from C) + 6 (from O) = 10 valence electrons
However, CO also has a formal charge distribution, meaning its most stable Lewis structure includes a triple bond and a lone pair on each atom, along with a formal charge. When drawn properly, the structure has:
- A triple bond between carbon and oxygen (1 sigma + 2 pi bonds).
- A lone pair on carbon and a lone pair on oxygen.
- A formal negative charge on carbon and a formal positive charge on oxygen.
So, the correct number of valence electrons in the Lewis structure is 10, not 14. But here’s the catch: the question option A says 14 valence electrons, which includes both bonding and nonbonding electrons, and is counted as total electrons in the structure (not just per atom). Let’s double-check:
- Triple bond = 6 electrons
- Lone pair on carbon = 2 electrons
- Lone pair on oxygen = 2 electrons
- Total = 6 (bonding) + 2 + 2 = 10 electrons
But this seems to contradict option A.
Upon a more accurate read, option A is actually incorrect. The correct answer should be:
E. This is a linear and polar molecule.
Corrected Answer: E.
CO is a linear molecule due to only two atoms being involved, which always makes the geometry linear. It is also polar due to the difference in electronegativity between carbon and oxygen and the uneven distribution of electrons (oxygen pulls electrons more strongly).
Therefore, the correct answer is E: This is a linear and polar molecule.
