Zinc acetate dihydrate (Zn(CH₃COO)₂·2H₂O)
Zinc acetate dihydrate (Zn(CH₃COO)₂·2H₂O) is a versatile inorganic salt commonly found in its dihydrate form. It is a white crystalline solid with a faint acetic acid odor and an astringent taste. This compound is widely used in various industrial, pharmaceutical, and dietary applications due to its unique chemical properties and stability.
Chemical Properties
Zinc acetate dihydrate has the molecular formula Zn(CH₃COO)₂·2H₂O and a molecular weight of approximately 219.50 g/mol. It is a monoclinic crystal with a density of 1.735 g/cm³. This compound decomposes at temperatures above 237°C. It is highly soluble in water, with a solubility of about 430 g/L at 20°C. Additionally, it is soluble in ethanol.
Synthesis Methods
Zinc acetate dihydrate is typically synthesized by reacting zinc oxide (ZnO) with glacial acetic acid (CH₃COOH). The reaction produces zinc acetate, which then crystallizes to form the dihydrate. The process involves subsequent crystallization, separation by centrifugation, and drying of the crystals. This method ensures high purity without the use of organic solvents.
Applications
Zinc acetate dihydrate has a wide range of applications across different industries:
Pharmaceutical and Dietary Uses:
It is used as a dietary supplement to treat zinc deficiencies. Zinc is essential for the synthesis of cholesterol, protein, and fats.
Zinc acetate is used in lozenges for treating the common cold. It is also used in oral capsules for the treatment of Wilson’s disease.
In topical formulations, it is used as an astringent and in combination with antibiotics for treating acne.
Industrial Applications:
It is used as a mordant in dyeing textiles and as a wood preservative.
Zinc acetate dihydrate is a key component in the production of other zinc salts and polymers. It is also used in the manufacturing of glazes for painting on ceramics.
In the nuclear industry, it serves as a plating inhibitor in power plants.
Analytical and Laboratory Uses:
It is used as an analytical reagent for testing albumin, tannin, and phosphate.
Zinc acetate dihydrate is used in the preparation of layered Zn-arylphosphonates, which have potential applications in sorption, ion exchange, and catalysis.
Safety Information
Zinc acetate dihydrate is generally considered safe for its intended uses. However, it can cause mild irritation to the throat and nose if inhaled. Ingestion may lead to irritation of the alimentary tract and vomiting. It is non-flammable and has an LD50 oral toxicity of 2.46 g/kg in rats. In case of contact with eyes or skin, immediate rinsing with water is recommended.
Storage and Handling
Zinc acetate dihydrate should be stored in a cool, dry place between +5°C and +30°C. It is stable under recommended storage conditions but should be kept away from strong oxidizing agents and alkalies. Proper handling and storage practices are essential to maintain the quality and safety of the product.
Environmental Considerations
Zinc acetate dihydrate is toxic to aquatic life, and its discharge into the environment should be avoided. It is biodegradable, with a biodegradability rate of 99% in aerobic conditions. However, it is not considered persistent, bioaccumulative, or toxic (PBT) at levels above 0.1%.
In summary, zinc acetate dihydrate is a valuable compound with diverse applications in pharmaceuticals, industry, and laboratories. Its stability, solubility, and synthesis methods make it a reliable choice for various uses, while its safety profile ensures minimal risks when handled properly.