(NH4)2S is a chemical equation that represents the chemical compound known as ammonium sulfide. Ammonium sulfide is a colorless or yellow liquid that smells like rotten eggs or ammonia. It is an acidic and flammable substance that requires special handling. Manufacturers produce ammonium sulfide through a reaction of hydrogen sulfide and ammonia.
Ammonium sulfide is sometimes used in photography, metal finishing and the creation of textiles. Ammonium sulfide is also commonly used for pranks, creating the foul scent for which stink bombs are known. This chemical is also known as "diammonium sulfide," a name that more accurately represents its chemical formula.
The chemical formula of ammonium sulfide is represented by two parts. Ammonia is signified by NH4, and the two outside the parentheses means that ammonium sulfide is made of two parts ammonia. Sulfur is represented by S in the formula, meaning the chemical is one part sulfur. Chemical formulae are used in chemistry for chemical equations and labelling chemicals in a clear and concise manner. Like ammonium sulfide, every known chemical has a formula indicating all of the elements that compose that chemical. Some chemical formulae are very large, particularly in biochemicals, but some are very simple, such as ammonium sulfide.