Title: Cobaltous Sulfate
CAS Registry Number: 10124-43-3
Molecular Formula: CoO4S
Molecular Weight: 155.00
Percent Composition: Co 38.02%, O 41.29%, S 20.69%
Line Formula: CoSO4
Literature References: Hexahydrate occurs in nature as the mineral bieberite. Prepn: Clark et al., J. Am. Chem. Soc. 42, 2483 (1920); Hammel, Ann. Chim. 11, 247 (1939); Gmelins, Cobalt (8th ed.) 58, (part A) 324-336 (1932) and supplement, 628-647 (1961). Review: de Bie, Doyen, Cobalt 15, 3-13; 16, 3-15 (1962).
Properties: Red to lavender dimorphic, orthorhombic crystals. d425 3.71. Stable to 708°. Dissolves slowly in boiling water.
Density: d425 3.71
Derivative Type: Monohydrate
Properties: Rose-colored, monoclinic crystals. Structure reported to be Co(H2SO5). d425 3.08. Dissolves slowly in boiling water.
Density: d425 3.08
Derivative Type: Heptahydrate
CAS Registry Number: 10026-24-1
Properties: Pink to red monoclinic, prismatic crystals. On heating dehydrates to the hexahydrate (monoclinic, prismatic crystals) at 41.5°, and to the monohydrate at 71°. d425 2.03. Sol in water; slightly sol in methanol, ethanol.
Density: d425 2.03
CAUTION: Cobaltous sulfate is reasonably anticipated to be a human carcinogen: Report on Carcinogens (PB2005-104914, 2004) p III-70.
Use: Usual source of water-soluble cobalt since it is the most economical and it shows less tendency to deliquesc or dehydrate than the chloride or nitrate. Used in storage batteries; in Co-electroplating baths; as drier for lithographic inks, varnishes; in ceramics, enamels, glazes to prevent discoloring; in Co pigments for decorating porcelain. |