NH42SeO4

NH42SeO4 is commonly written as (NH4)2SeO4 and is the ammonium salt of selenic acid, i.e., ammonium selenate. It consists of two ammonium cations (NH4+) and one selenate anion (SeO4 2−). The compound is a white, odorless crystalline solid that is highly soluble in water. Its approximate molar mass is 179.06 g/mol.

Preparation and occurrence: (NH4)2SeO4 can be prepared by neutralizing selenic acid (H2SeO4) with ammonium hydroxide or ammonium carbonate, for example: H2SeO4 + 2 NH4OH → (NH4)2SeO4 + 2 H2O. It is not typically mined as a mineral, but is produced commercially for laboratory use and agricultural applications as a selenium source.

Properties and behavior: In aqueous solution it dissociates into NH4+ and SeO4 2− ions. The solid is stable at room temperature, but ammonium salts generally decompose upon strong heating, releasing ammonia and other products. It is compatible with many inorganic salts but should be kept away from strong reducing agents and organic materials.

Applications: Ammonium selenate serves as a source of selenium in fertilizers and animal feeds, providing micronutrients essential for biology. It may also be used in chemical synthesis and analytical procedures requiring a soluble selenium source.

Safety: Selenium compounds are potentially toxic; exposure should be minimized. Handle with appropriate protective equipment, avoid ingestion and inhalation, and store away from incompatible materials. Proper disposal and regulatory compliance are advised for waste containing ammonium selenate.