Sulfurous Acid (original) (raw)
Last Updated : 23 Jul, 2025
Sulfurous Acid or Sulphurous Acid is a chemical acid consisting of the elements Hydrogen, Sulfur, and Oxygen. It is a common fruit and vegetable preservative. Hydrogen is a colorless, odorless, tasteless, and flammable gas. Its atomic number is 1 and is represented with the symbol H. Sulfur is an abundant non-metal present in Group 16 of the periodic table. Its atomic number is 16 and is represented by the symbol S. Oxygen is present in Group 16 of the periodic table. Its atomic number is 8 and is represented by the symbol O.
In this article, we will learn about, Sulfurous Acid, Sulfurous Acid Chemical Formula, Physical and Chemical Properties of Sulfurous Acid, and others in detail.
Table of Content
- What is Sulfurous Acid (H2SO3)?
- Sulfurous Acid Formula
- Preparation of Sulfurous Acid
- Structure of Sulfurous Acid
- Properties of Sulfurous Acid
- Uses of Sulfurous Acid
What is Sulfurous Acid (H2SO3)?
Sulfurous Acid is a colorless, weak inorganic acid with a pungent burning sulfur smell. The chemical formula of Sulfurous Acid is H2SO3.
It is corrosive to metals and tissues. H2SO3 is a sulfur oxoacid, tautomer of a sulfonic acid, and conjugate acid of a Hydrogen sulfite. The other names for Sulfurous Acid are hydrogen thiosulfate, Sulfur Dioxide solution, and Trioxosulfuric Acid. It is an intermediate species that forms Acid rain from SO2 (Sulfur dioxide).
Sulfurous Acid Formula
Tbe formula for Sulfurous Acid is, H2SO3 it contains 2 Hydrogen atom, 1 Sufur atom and 3 Oxygen atom. The molecular mass of Sulfurous Acid is 82.07 g/mol.
**Preparation of Sulfurous Acid (H2SO3)
Sulfurous Acid is prepared using the method as,
- Sulfurous Acid (H2SO3) is prepared by dissolving Sulfur dioxide (SO2) in water (H2O). The chemical reaction is given below,
**SO 2 + H 2 O ⇢ H 2 SO 3
Structure of Sulfurous Acid (H2SO3)
Sulfurous acid has the chemical formula H2SO3 and a molar mass of 82.07 g/mol. The chemical structure is illustrated in the diagram below. It comprises one sulfur atom with two single bonds to hydroxyl groups and one double bond to oxygen. The image of the Sulfurous acid is shown in the image added below.
Properties of Sulfurous Acid (H2SO3)
The physical and the chemical properties of the Sulfurous acid are added in the article below,
Physical Properties of Sulfurous Acid
Various physical properties of the Sulfurous Acid are,
- Sulfurous Acid is a colorless liquid.
- Sulfurous Acid has a pungent odor.
- Molecular weight of Sulfurous Acid is 82.07 g/mol.
- Monoisotopic mass of Sulfurous Acid is 81.97 g/mol.
- Boiling point of Sulfurous Acid is -60 °C.
- Density of Sulfurous Acid is 1.03 g/mL.
Chemical Properties of Sulfurous Acid
Various chemical properties of the Sulfurous acid are,
- Sulfurous Acid is unstable and has never been isolated in its pure state. H2SO3 decomposes into Sulfur dioxide and Water. The chemical reaction is given below-
**H 2 SO 3 ⇢ SO 2 +H 2 O
- Sulfurous Acid when exposed to air turns out to be Sulfuric Acid.
**2H 2 SO 3 + O 2 ⇢ 2H 2 SO 4
Uses of Sulfurous Acid (H2SO3)
Sulfurous Acid (H2SO3) has various uses and some of its common uses are,
- Sulfurous Acid is used in manufacturing paper products.
- H2SO3 and its salts are used as powerful reducing agents and disinfectants.
- H2SO3 is used as an intermediate in industries.
- Sulfurous Acid is a mild bleaching agent for applications with chlorine-sensitive materials.
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