Title: Cobaltic Potassium Nitrite
CAS Registry Number: 13782-01-9
CAS Name: Hexakis(nitrito-N)cobaltate(3-) tripotassium
Additional Names: potassium hexanitrocobaltate(III); potassium cobaltinitrite; potassium nitrocobaltate(III); cobalt yellow; Fischer's yellow; C.I. Pigment Yellow 40; C.I. 77357
Molecular Formula: CoK3N6O12
Molecular Weight: 452.26
Percent Composition: Co 13.03%, K 25.94%, N 18.58%, O 42.45%
Line Formula: K3Co(NO2)6
Literature References: Incorrectly called "Indian Yellow". Prepd by addition of KNO2 to a solution of a Co salt: Salyer, Sweet, Anal. Chem. 32, 548 (1962).
Properties: Sesquihydrate, yellow, octahedral, cubic crystals. Very slightly sol in water, dil acetic acid. Practically insol in alcohol; dec by mineral acids.
Use: As an oil- and water-color pigment; in painting on glass and porcelain; in coloring rubber; in separation of Co from Ni; in Co analysis.