What is Na2S2O4? Important knowledge about Na2S2O4.

1. Definition of Na₂S₂O₄

Na₂S₂O₄, commonly known as Sodium Hydrosulfite or Sodium Dithionite. It is a chemical compound consisting of two sodium atoms, two sulfur atoms, and four oxygen atoms, with a total molecular weight of 174.107 g/mol. Its molecule is constructed from two Na+ ions and one S₂O₄₂- ion.

2. Properties of Na₂S₂O₄

2.1 Physical properties: Na₂S₂O₄ is a solid, forming colorless crystals, odorless and having a neutral PH state.

2.2 Chemical properties: Na₂S₂O₄ is very easily reduced in air, especially under high temperature and humidity conditions. It reacts with strong acids to produce SO₂ and with water to produce sodium sulfide, hydrogen sulfide and SO₂.

3. Common Chemical Equations:

Reaction with strong acid: 2Na₂S₂O₄ + H₂SO₄ -> 2Na₂SO₄ + 2SO₂ + 2H₂O

Reaction with water: 2Na₂S₂O₄ + H₂O -> Na₂SO₄ + Na₂S + SO₂ + 2H₂O

4. Synthesis of Na₂S₂O₄

4.1 Laboratory synthesis: Na₂S₂O₄ is not commonly synthesized in the laboratory due to its instability and flammability.

4.2 Industrial synthesis: Na₂S₂O₄ is produced from sodium bisulfite (NaHSO₃) and zinc, according to the reaction: 2NaHSO₃ + Zn -> Na₂S₂O₄ + Zn(OH)₂.