Synonyms: Fumarate ; Fumarate dianion ; Fumarate(2-) ; Fumaric acid, ion(2-) ; 2-Butenedioic acid (E)-, ion(2-)
Molecular Formula: C₄H₂O₄
Molecular Weight: 114.056280 g/mol
Canonical SMILES: [O-]C(=O)\C=C\C([O-])=O 
Flash Point: 183 °C
Molecular Weight: 114.0574 g/mol
Enthalpy of Vaporization: 65.99 kJ/mol
Boiling Point: 355.5 °C at 760 mmHg
Vapour Pressure of Fumarate (CAS NO.142-42-7 ) : 5.19E-06 mmHg at 25 °C

 Fumaric acid  is an acid of Fumarate. It is a white crystalline compound. Fumaric acid, when added to food products, is an acidity regulator denoted by E number E297. Fumaric acid esters are sometimes used to treat psoriasis, as it has been suggested that the condition is caused by an impairment of fumaric acid production in the skin. It's side-effects include kidney or gastrointestinal disorders, as well as skin flushing; these are mainly caused by excess intake.Fumaric acid is also used in the manufacture of polyester resins and polyhydric alcohols and as a mordant for dyes.