Ammonium sulfate (uh-MOH-ni-um SUL-fate) is an odorless, colorless to white crystalline solid that occurs in nature as the mineral mascagnite. In 2004, 2.6 million metric tons (2.9 million short tons) of the compound were produced in the United States, placing it in 21st place among chemicals made in that year. More than 95 percent of the ammonium sulfate produced is used in the production of fertilizers.
diammonium sulfate; sulfuric acid, diammonium salt
(NH4)2SO4
Nitrogen, hydrogen, sulfur, oxygen
Inorganic salt
Solid
132.14 g/mol
Not applicable; decomposes above 235°C (455°F)
Not applicable
Soluble in water; insoluble in alcohol, acetone, and other common organic solvents
The primary method of preparation for ammonium sulfate is the direction reaction between ammonia gas (NH3) and sulfuric acid (H2SO4). The ammonium sulfate produced in the reaction is recovered as white crystals after evaporation of the water present in the reaction mixture. Other methods of preparation are also used. For example, gypsum (CaSO4·2H2O) can be treated with ammonia (NH3) and carbon dioxide (CO2) to generate ammonium sulfate.
Ammonium sulfate is used as a fertilizer because it supplies nitrogen and sulfur, two nutrients that plants need to grow properly. Lesser quantities of the compound are utilized in water treatment plants where it is used to control the acidity of the water being processed. Among other uses of ammonium sulfate are:
The German alchemist Andreas Libau (c.1540–1616), better known by his Latinized name of Libavius, wrote what is widely regarded as the first textbook on chemistry in 1597. In that book, Alchemia, he described a method for making ammonium sulfate, probably the first mention of the compound in modern sources.
"Ammonium Sulfate." Hazardous Substances Data Bank. http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@na+Ammonium+Sulfate (accessed on September 20, 2005).
"Ammonium Sulfate Advantage: FAQs." Honeywell. http://www.sulfn.com/main/pages/faqs.asp (accessed on July 22, 2005).
"Ammonium Sulfate Industrial Grade." BASF. http://www.basf.de/en/produkte/chemikalien/anorganika/ammonium/ammoniumsulfat_industrial.htm?id=V00-YYuHV7-Ro7bsf1Gb (accessed on September 20, 2005).
Bariyanga, Joseph. "Fertilizer." Chemistry: Foundations and Applications. Edited by J. J. Lagowski. Vol. 2. New York: Macmillan Reference USA, 2004.
See AlsoAmmonia; Sulfuric Acid