What is a Sulfurous acid (H₂SO₃)?

Sulfurous acid (H₂SO₃) is a chemical compound that exists as a colorless or pale yellow liquid. When dissolved in water, it forms a solution known as sulfurous acid solution, and it is a strong reducing agent. Sulfurous acid is often encountered in the form of its salts, such as sodium bisulfite (NaHSO₃) or sodium sulfite (Na₂SO₃).

Main uses:
✅ Bleaching agent:
Sulfurous acid is used as a bleaching agent, especially for bleaching wood, textiles, and paper.
✅ Food preservation:
Sulfite salts, such as sodium bisulfite and sodium sulfite, are used as preservatives in foods like wine and dried fruits.
✅ Chemical reactions:
Sulfurous acid is used in reduction reactions and neutralization processes and serves as a reagent in chemical industries.
✅ Water treatment:
It is also used in some water treatment applications.

Safety notes:
✅ Toxicity:
Sulfurous acid itself is toxic, and inhalation or skin contact may irritate the respiratory system or skin. Proper handling and safety precautions are necessary.
✅ Oxidation:
Sulfurous acid is prone to oxidation, and proper precautions should be taken when handling it.

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