Sulfate is the IUPAC name for the SO42- ion, consisting of a central sulfur atom single bonded to four tetrahedrally oriented oxygen atoms. This anion has a net negative two electric charge.

Almost all ionic compoundss with sulfate anions are soluble in water at standard temperature and pressure (the exceptions include CaSO4, SrSO4, and BaSO4).

The acid of the sulfate ion is H2SO4, called sulfuric acid.

Sulfates are important in both chemical industry and biological systems:

  • Lead batteries typically use sulfuric acid.
  • Organisms living near deep sea thermal vents depend on sulfates for energy in lieu of the sun.
  • Copper sulfate is a common algaecide.
  • Magnesium sulfate, commonly known as Epsom salts, is used as a therapeutic bath.