Ammonium sulfate

Ammonium sulfate,CAS No.: 7783-20-2, with the chemical formula (NH4)2SO4 and a molecular weight of 132.14, is a colorless rhombic crystal at room temperature. Industrial products are generally white or slightly yellowish small crystals, although some by-products may have a bluish or dark brown color. It has a relative density of 1.77 and a melting point of 280°C (decomposition). It is highly soluble in water but insoluble in ethanol and acetone. Its aqueous solution is acidic (pH = 5.5, 0.1 mol/L), and its solubility in water decreases with an increase in ammonia content. Ammonium sulfate is hygroscopic and can solidify into lumps when exposed to moisture. Chemically, it exhibits the properties of both ammonium salts and sulfates, reacting with bases to release ammonia gas, decomposing upon heating into ammonia, nitrogen, and sulfur dioxide, forming a barium sulfate precipitate with barium chloride, and generating a brown precipitate with potassium iodide mercuric nitrate solution.

Ammonium sulfate contains approximately 21% nitrogen and is a fast-acting fertilizer suitable for most crops. It is also used in the salt precipitation process in the pharmaceutical industry, in the cultivation of yeast for fresh yeast production, as a flux in soldering, a fire retardant for fabrics, a catalyst for food coloring, an auxiliary dye for acid dyes, and a dehairing agent for leather.