Question

What is the formal charge of the atom labeled A in the image? Report your answer as an integer without any decimal places. A Lewis structure is shown. An N atom is in the center and is labeled “B.” The N atom is single-bonded to an O atom to the left. The O atom has 3 pairs of electrons and is labeled “A.” The N atom is single-bonded to another O atom with 3 pairs of electrons towards the bottom of the image. The N atom is double-bonded to a third O atom with 2 pairs of electrons to the right of the image. The rightmost O atom is labeled “C.” Provide your answer below:

Answer 1

In the Lewis structure, atom A represents an oxygen (O) atom bonded to the nitrogen (N) atom in the center. To determine the formal charge of atom A, the number of valence electrons on the free atom minus the assigned electrons in the structure is calculated. The formal charge of atom A is then determined to be -1.

In the given Lewis structure, oxygen atom A has three lone pairs of electrons (6 electrons) and forms a single bond with the nitrogen (N) atom in the center. The single bond contributes one electron to atom A. The adjacent nitrogen atom is also bonded to two other oxygen atoms, forming a double bond with one and a single bond with the other.

To calculate the formal charge of atom A:

The number of valence electrons on a free oxygen atom is 6.

Atom A has 6 electrons from its lone pairs and 1 electron from the single bond.

The formal charge is calculated as 6−6−1=−1.

Therefore, the formal charge of atom A in the Lewis structure is -1. This indicates that atom A has gained one electron more than its neutral state, contributing to the overall charge distribution within the molecule.