Knowledge

Is Sulfur Dioxide the Same as Sodium Metabisulfite?

No, sulfur dioxide (SO₂) and sodium metabisulfite (Na₂S₂O₅) are not the same, but they are closely related and often used for similar purposes, especially in food preservation and winemaking.

• Sulfur Dioxide (SO₂): A gas used as a preservative and antioxidant. It can be directly added or produced in situ.
• Sodium Metabisulfite (Na₂S₂O₅): A solid chemical compound that, when dissolved in water, releases sulfur dioxide gas.

Key Relationship: Sodium metabisulfite is often used because it conveniently generates sulfur dioxide when mixed with water. While they are different substances, they serve similar functions due to this chemical reaction.

Summary: Sulfur dioxide and sodium metabisulfite are not the same, but sodium metabisulfite acts as a source of sulfur dioxide in many applications.