is conjugate acid of is conjugate base of fumaric acid fumarate(2-) fumarate(1-) (2E)-3-carboxyacrylate (2E)-3-carboxyprop-2-enoate 115.003 115.06422 A hydrogen butenedioate obtained by deprotonation of one of the carboxy groups of fumaric acid. Beilstein:1906438 C4H3O4 CHEBI:37154 Gmelin:325290 InChI=1S/C4H4O4/c5-3(6)1-2-4(7)8/h1-2H,(H,5,6)(H,7,8)/p-1/b2-1+ OC(=O)\C=C\C([O-])=O Reaxys:1906438 VZCYOOQTPOCHFL-OWOJBTEDSA-M chebi_ontology fumarate monoanion hydrogen fumarate hydrogen butenedioate