Sodium hydrosulfite
General Product Information
| Article | Sodium hydrosulfite |
| Synonyms | Sodium dithionite, Sodium sulfoxylate |
| CAS No. | 7775-14-6 |
| EEG No. | 016-028-00-1 |
| EINECS No. | 231-890-0 |
| IMO | Class 4.2 |
| Tariff Code | 28311000 |
| UN No. | 1384 |
| VLG/ADR | Class 4.2, Packing Group II |
Description
Sodium hydrosulfite is a white to pale yellow crystalline powder, mainly used as a powerful reducing agent in industrial processes. Due to its Chemical Structure, it has a strong affinity for oxygen, allowing it to effectively remove oxygen or dyes from fabrics.
Characteristics
- Odor: Slightly sulfurous.
- Hygroscopic: –
- Color: White to light yellow.
- Grade: Technical.
- Solubility: Soluble in water.
- Shape: Crystalline powder.
Physical & Chemical Properties
| Chemical Structure | Na2S2O4 |
| Molar Weight | 174.11 g/mol |
| Melting Point | >150 °C (decomposes) |
| Boiling Point | – |
| Density | – |
| Refractive Index | – |
| pH | – |
Applications
Sodium hydrosulfite is applied in various ways, for instance:
1. Chemical Industry
Reducing agent at synthesis of dyes, pigments, and other organic compounds.
2. Water Treatment
Removes dissolved oxygen and residual chlorine in industrial plants.
3. Paper Industry
For bleaching recycled paper and pulp.
4. Textile Industry
Used for reductive bleaching processes of cotton, wool and synthetic fibers.
Interessing Links
- CAS Common Chemistry – Sodium Dithionite
- European Chemicals Agency (ECHA) – For chemical information and regulations.
- PubChem – Sodium Dithionite – Chemical information by the National Library of Medicine of the National Center for Biotechnology Information (NIH-NCBI).
- Wikipedia – Sodium dithionite