How to calculate formal charges of carbon monoxide (CO) with lewis structure?
In covalently bonded molecules, formal charge is the charge assigned to an atom based on the assumption that the bonded electrons are equally shared between concerning atoms, regardless of their electronegativity.
The overall formal charge present on a molecule is a measure of its stability.
The fewer the formal charges present on the bonded atoms in a molecule (close to zero), the greater the stability of its Lewis structure.
In this article, we will calculate the formal charges present on the bonded atoms in CO and also the overall charge present on the molecule.
The formal charges can be calculated using the formula given below:
The formal charge of an atom = [valence electrons of an atom – non-bonding electrons – ½ (bonding electrons)]
The valence electrons (V.E) of an atom are the total number of electrons present in its valence shell. Valence electrons can be determined by locating the position of the elemental atom in the Periodic Table.
Non-bonding electrons(N.E) are the number of lone pairs present on the atom. (1 lone pair means 2 nonbonding electrons).
Bonding electrons (B.E) are the total electrons shared with the atom via covalent chemical bonds. (1 single bond means 2 bonding electrons).
Now let us use this formula to calculate the formal charges in the most preferred Lewis structure of carbon monoxide, i.e., CO.
The most preferred Lewis representation of CO is as shown below.
It consists of a total of 10 valence electrons. The molecule consists of only two atoms; one carbon (C) atom, which is bonded to one atom of oxygen (O) via a triple covalent bond.
One lone pair of electrons is present on the C-atom and also on the O-atom.
It is the best possible Lewis structure of CO because the formal charges are minimized in it, and thus, it is the most stable.
Let’s find out how we can determine the formal charges present on each atom in the CO Lewis structure.
Formal charge on the Oxygen atom = 6 – 2 – 6/2 = 6 – 2 – 3 = 6 – 5 = +1
∴ The formal charge on the double-bonded oxygen (O) atom in CO is +1.
The above calculation shows that a -1 formal charge is present on the C-atom while a +1 formal charge is present on the O-atom in CO Lewis structure, as shown below.
When both formal charges are added up [(-1) +(+1) = 0], it results in a zero formal charge overall. Consequently, there is no overall formal charge on the CO Lewis structure denoting carbon monoxide is a neutral molecule.
Vishal Goyal is the founder of Topblogtenz, a comprehensive resource for students seeking guidance and support in their chemistry studies. He holds a degree in B.Tech (Chemical Engineering) and has four years of experience as a chemistry tutor. The team at Topblogtenz includes experts like experienced researchers, professors, and educators, with the goal of making complex subjects like chemistry accessible and understandable for all. A passion for sharing knowledge and a love for chemistry and science drives the team behind the website. Let's connect through LinkedIn: https://www.linkedin.com/in/vishal-goyal-2926a122b/
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