What is the formula for sulfurous acid?

The formula for sulfurous acid is H2SO3. It is a weak acid that is formed when sulfur dioxide (SO2) is dissolved in water. The molecule consists of two hydrogen atoms (H) attached to a central sulfur atom (S), which is bonded to three oxygen atoms (O). Sulfurous acid is a colorless liquid that is used in the production of paper, detergents, and food preservatives. It can also be found in the atmosphere as a result of volcanic activity or industrial emissions. Sulfurous acid is unstable and rapidly decomposes into sulfuric acid (H2SO4) and water (H2O) when exposed to air or heated.