What is the overall charge of the sulfite ion, SO3^2-?

The overall charge of the sulfite ion, represented as SO₃²⁻, is correctly identified as 2-. This is determined by examining both the charges associated with the sulfur and oxygen atoms in the ion.

Sulfur, which is the central atom in the sulfite ion, typically has an oxidation state of +4 in this molecular structure. Each oxygen atom has an oxidation state of -2. In the sulfite ion, there are three oxygen atoms:

• Contribution from sulfur: +4
• Contribution from three oxygen atoms: 3 × (-2) = -6

When these contributions are added together to find the overall charge:

+4 (from sulfur) + (-6 from oxygen) = -2

This results in an overall charge of 2- for the sulfite ion. Understanding how the charges from individual atoms combine to yield the charge of a polyatomic ion is key to evaluating the charge correctly.