- Zinc ammonium sulfate, also known as zinc diammonium sulfate or zinc ammonium alum, is an inorganic compound with the chemical formula (NH₄)₂Zn(SO₄)₂·6H₂O. It is a type of double salt, composed of zinc sulfate and ammonium sulfate, typically found in the form of colorless to white crystalline solids. This compound is structurally similar to other alums and belongs to a broader class of compounds known as Tutton salts, which have the general formula M₂M'(SO₄)₂·6H₂O, where M is a monovalent cation (such as NH₄⁺) and M’ is a divalent cation (such as Zn²⁺).
- Zinc ammonium sulfate forms large, well-defined crystals that are often used for educational demonstrations of crystal growth. It is soluble in water and exhibits typical behavior of hydrated salts, where heating results in loss of water molecules followed by decomposition of the salt. In solution, the compound dissociates into zinc, ammonium, and sulfate ions. The presence of both zinc and ammonium ions gives it unique physicochemical properties that can be exploited in laboratory or industrial processes.
- In terms of applications, zinc ammonium sulfate is primarily of academic interest, especially in crystal chemistry and coordination chemistry. It may occasionally be used in electroplating processes, analytical chemistry, or as a reagent in laboratory experiments involving precipitation reactions or the study of ionic equilibria. Additionally, its similarity to other alums allows it to serve as a reference or comparative material in studies involving crystal structures and ionic interactions.
- From a safety perspective, zinc ammonium sulfate should be handled with care. Although not classified as highly hazardous, ingestion or inhalation of dust can cause irritation, and prolonged exposure may have mild toxic effects due to the presence of zinc and ammonia. It should be stored in a cool, dry place, away from incompatible substances such as strong acids or oxidizing agents. Proper laboratory safety procedures should be followed when working with this compound.
