Sulfurous Acid (H2SO3)
Definition - What does Sulfurous Acid (H2SO3) mean?
Sulfurous Acid is a chemical compound that is obtained when sulfur dioxide gas is dissolved in water. Its chemical formula is H2SO3. The compound is quite unstable and it easily decomposes back into water and sulfur dioxide. It is mainly used as a disinfectant and a reducing agent. It is also used as mild bleaching agent where the chlorine-based bleaches cannot be used.
Petropedia explains Sulfurous Acid (H2SO3)
When sulfur dioxide gas is dissolved in water, the water becomes acidic in nature and the solution is called sulfurous acid. It is quite difficult to test the pH level of sulfurous acid as it is a weak and unstable acid which easily transforms back into SO2 and H2O. The compound is only formed in an aqueous solution and cannot be isolated in its pure form. The solution contains H+ and HSO3—ions and is an intermediate species in the formation of acidic rain. When an oxygen atom is donated to the compound it gets oxidized and forms sulfuric acid.