What is the name of the acid with the formula H2SO3?

The name of the acid with the formula H₂SO₃ is c) sulfurous acid.

To understand why, let’s break it down:

• H₂SO₃ contains sulfur (S) and two types of oxygen atoms.
• This compound is typically found in a state where sulfur has an oxidation state of +4.
• When naming acids derived from sulfur oxides, specific naming conventions apply:

Compounds like H₂SO₄ (which has sulfur in the +6 oxidation state) are called sulfuric acid, while H₂SO₃ indicates a lower oxidation state and is thus called sulfurous acid.