Sulfate ion
Charge: 2- · Type: Polyatomic anion · Molar mass: 96.056 g/mol
Made of: sulfur, oxygen
How it forms
Sulfuric acid loses two protons to give SO4^2-. The sulfur atom sits at the center of a tetrahedron of oxygen atoms, with the charge spread over all four oxygens by resonance.
Naming note
SO4^2- is the sulfate ion; SO3^2- is sulfite. Sulfuric acid's salts are all named as sulfates.
Examples in compounds
Copper(II) sulfate
Calcium sulfate
Sodium sulfate