Cobalt(II) acetate

  • Cobalt (II ) acetate
  • Cobalt acetate
  • 71-48-7 (anhydrous)
  • 6147-53-1 (tetrahydrate )
  • Pink solid ( anhydrous)
  • Red to purple solid (tetrahydrate )

Fixed

140 ° C

  • Slightly soluble in water ( 380 g · l-1 tetrahydrate at 25 ° C)
  • Slightly soluble in acetic acid and pyridine

Risk

503 mg · kg -1 ( LD50, rat, oral)

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Cobalt (II ) acetate is a chemical compound selected from the group consisting of cobalt compounds and acetates.

Production and representation

The production of cobalt ( II) acetate tetrahydrate, by the reaction of the cobalt (II ) oxide with acetic acid, was first mentioned in 1777:

The crystal water content was first determined in 1878 by H. Stallo. Today the usual method of presentation of the tetrahydrate is the reaction of the cobalt (II ) carbonate with acetic acid.

Anhydrous cobalt can be obtained by reaction of cobalt (II ) nitrate are produced with acetic anhydride.

Properties

The tetrahydrate crystallizes in the monoclinic crystal system, space group P21 / c with lattice parameters a = 477.4 pm, b = 1184.3 pm, c = 829.0 pm, and β = 93.14 °. In the unit cell contains two formula units. The crystals are isomorphous to nickel ( II) acetate.

There is further also a basic cobalt ( II) acetate with the composition Co5 (OH ) 2 ( CH3COO ) 8 It crystallizes as a dihydrate, originating from the decomposition of cobalt (III ) acetylacetonate.

Ammonium chromate with cobalt ( II) acetate is a double salt of the composition (NH 4 ) 2 CO ( CrO4 ) 2.6 H2O, the crystallized brown yellow prisms.

When heated, cobalt ( II ) acetate tetrahydrate are initially from its water of crystallization. The dehydration is complete at 150 ° C and proceeds in two stages - it forms an intermediate hemihydrate Co ( CH3COO ) 2 · H2O 0.5. Upon further heating of the anhydrous compound is formed, a basic acetate with the stoichiometric composition of the Co (OH ) ( CH 3 COO ). As the final product of the decomposition occurs in a hydrogen atmosphere of elemental cobalt, in a nitrogen atmosphere the cobalt (II ) oxide and in the air, cobalt ( II, III ) oxide, Co3O4.

Use

Cobalt (II ) acetate is used as a bleaching and drying agent for paints and varnishes, and as a catalyst in the production of adipic acid.

CAS registry number PubChem Dangerous Substances Directive (67/548/EEC) Chemical reaction Cobalt(II) oxide Cobalt(II) carbonate Cobalt(II) nitrate Isomorphism (crystallography) Dehydration reaction Digital Object Identifier Inorganic Chemistry (journal)
195289
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