For chemists, R&D scientists, and procurement specialists in the chemical industry, a deep understanding of the properties and synthesis of raw materials is fundamental. Sodium Metabisulfite (SMBS), represented by the chemical formula Na2S2O5, is an inorganic compound with a fascinating chemical profile that underpins its wide range of applications. As a dedicated manufacturer in China, we specialize in producing high-purity SMBS and are pleased to share insights into its science.

Sodium Metabisulfite is essentially a salt of sulfurous acid, formed by the reaction of sulfur dioxide with sodium carbonate or sodium hydroxide. Its molecular structure, featuring a metabisulfite anion (S2O5^2-), is key to its reactivity. When you buy Sodium Metabisulfite, you are acquiring a compound that offers significant utility due to its reducing and preservative capabilities.

Understanding the Chemical Properties of Sodium Metabisulfite:

  • Chemical Formula: Na2S2O5
  • Appearance: Typically a white or slightly yellowish crystalline powder.
  • Odor: Possesses a characteristic, faint sulfur dioxide smell, especially when exposed to moisture or acids.
  • Solubility: Highly soluble in water, with solubility increasing with temperature. It is also soluble in glycerol but only slightly in ethanol.
  • pH: Aqueous solutions are acidic, typically with a pH between 4.0 and 5.5 for a 5% solution.
  • Reactivity:
    • Decomposition: When heated above its decomposition point (around 150°C), it breaks down to form sodium sulfite and sulfur dioxide gas.
    • Reaction with Water: In water, it hydrolyzes to form sodium bisulfite (NaHSO3), releasing sulfurous acid, which then dissociates. This is the source of its acidic nature and the release of SO2.
    • Reaction with Acids: Reacts vigorously with acids to liberate sulfur dioxide gas.
    • Reducing Agent: It is a strong reducing agent, capable of reducing various oxidizing agents. This property is fundamental to its use in applications like dechlorination and as an antioxidant.

Synthesis and Manufacturing:

The commercial production of Sodium Metabisulfite typically involves reacting sodium sulfite or sodium bisulfite solutions with sulfur dioxide. A common industrial process involves:

  1. Reacting sodium carbonate with sodium bisulfite solution to form sodium sulfite.
  2. Saturating this solution with sulfur dioxide to convert sodium sulfite into sodium bisulfite.
  3. Cooling the sodium bisulfite solution to precipitate Sodium Metabisulfite (Na2S2O5) through a self-reaction or by adding a catalyst, followed by purification and drying.

The availability of high-purity SMBS from reliable sources is crucial for industrial applications. As a direct manufacturer in China, we ensure stringent quality control throughout our production process, delivering a product that meets the demanding specifications of our clients. We offer competitive Sodium Metabisulfite prices and reliable supply chains for bulk orders.

For businesses requiring a high-quality, industrially relevant inorganic chemical, understanding the science behind Sodium Metabisulfite is key. If you are looking to source this compound, consider our expertise as a leading manufacturer and supplier. Contact us for detailed product specifications and to discuss your procurement needs.