METABISULFITE DE SOUDE ESSECO

Sodium metabisulfite, also known as sodium pyrosulfite or SMB, is an inorganic compound with the chemical formula Na2S2O5. It is a white crystalline solid with a sulfurous odor. It is a versatile compound with a wide range of applications in various industries.

Physical and Chemical Properties

• Appearance: White crystalline solid
• Odor: Sulfurous
• Molecular weight: 190.11 g/mol
• Melting point: 150 °C (302 °F)
• Boiling point: Decomposes at 520 °C (968 °F)
• Solubility in water: Very soluble (50 g/100 mL at 20 °C)
• Solubility in other solvents: Soluble in ethanol, methanol, and glycerol

Chemical Properties

Sodium metabisulfite is a strong reducing agent and a sulfite donor. It can react with various substances, including:

• Oxidizing agents: Sodium metabisulfite can reduce oxidizing agents, such as chlorine, to their lower oxidation states.
• Aldehydes and ketones: Sodium metabisulfite can add bisulfite ions to the carbonyl groups of aldehydes and ketones, forming addition products.
• Halogens: Sodium metabisulfite can react with halogens, such as chlorine and bromine, to form sulfurous acid and halides.

Applications

Sodium metabisulfite has a wide range of applications in various industries, including:

• Food and beverage industry: Sodium metabisulfite is used as a preservative in food and beverages to prevent browning and microbial growth. It is also used as a bleaching agent for fruits and vegetables.
• Photography industry: Sodium metabisulfite is used as a developing agent and fixer in photography. It helps to preserve the image and prevent fading.
• Water treatment industry: Sodium metabisulfite is used to remove chlorine from water. It is also used as a reducing agent in wastewater treatment.
• Textile industry: Sodium metabisulfite is used as a bleaching agent and dechlorinating agent in textile processing.
• Pharmaceutical industry: Sodium metabisulfite is used as an antioxidant and preservative in pharmaceutical preparations.

Safety

Sodium metabisulfite is an irritant to the skin, eyes, and respiratory tract. It should be handled with care and appropriate personal protective equipment should be used. Inhaling high concentrations of sodium metabisulfite can cause respiratory problems, including coughing, wheezing, and shortness of breath.

Storage

Sodium metabisulfite should be stored in a cool, dry, and well-ventilated place. It should be kept away from heat, moisture, and incompatible materials.

Conclusion

Sodium metabisulfite is a versatile and important compound with a wide range of applications in various industries. It is a valuable tool for preserving food, processing textiles, developing photographs, and treating water. However, it is important to handle sodium metabisulfite with care and follow safety precautions to avoid potential health hazards.