Synonyms: Ferrate(1-),bis[3-[4,5-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonamidato(2-)]-,sodium; Ferrate(1-), bis[3-[4,5-dihydro-4-[[2-(hydroxy-kO)-5-nitrophenyl]azo-kN1]-3-methyl-5-(oxo-kO)-1H-pyrazol-1-yl]benzenesulfonamidato(2-)]-,sodium (9CI); Benzenesulfonamide,3-[4,5-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]-,iron complex