Basic information Physical Properties Uses Preparation Reactions Safety Related Supplier
ChemicalBook >  Product Catalog >  Inorganic chemistry >  Inorganic bases >  Cobalt(II) hydroxide

Cobalt(II) hydroxide

Basic information Physical Properties Uses Preparation Reactions Safety Related Supplier
Cobalt(II) hydroxide Basic information
Cobalt(II) hydroxide Chemical Properties
  • Melting point:°Cd ec.)
  • Density 3.597 g/mL at 25 °C(lit.)
  • storage temp. Inert atmosphere,Room Temperature
  • form Powder
  • Specific Gravity3.597
  • color Pink to purple
  • Water Solubility Soluble in acids and ammonia. Very slightly soluble in water. Insoluble in dilute alkalis.
  • Sensitive Air Sensitive
  • Merck 14,2442
  • Solubility Product Constant (Ksp)pKsp: 14.23
  • Stability:Stability
  • CAS DataBase Reference21041-93-0(CAS DataBase Reference)
  • EPA Substance Registry SystemCobalt hydroxide (Co(OH)2) (21041-93-0)
Safety Information
MSDS
Cobalt(II) hydroxide Usage And Synthesis
  • Physical PropertiesTwo forms occur, a rose-red powder (more stable) and a bluish-green powder less stable than the red form; rhombohedral crystals; density 3.597 g/cm3; decomposes on heating; practically insoluble in water 3.2 mg/L; Ksp 1.0x10–15; soluble in acids and ammonia; insoluble in dilute alkalis.
    Cobalt(II) hydroxide
    The addition of alkali metal hydroxides to solutions of cobalt(II) salts results in the precipitation of cobalt(II) hydroxide in either a blue or pink form depending upon the conditions. The pink form is the more stable of the two and is obtained when a suspension of the blue form is allowed to stand or is warmed. Cobalt(II) hydroxide is amphoteric, dissolving in alkalis to form blue solutions of the [Co(OH)4]2~ ions. In the presence of alkali, suspensions of Co(OH)8 are oxidized by air to the brown CoO(OH), this oxidation being brought about rapidly by oxidants such as hypochlorite, bromine water or hydrogen peroxide. The pink Co(OH)2 (density 3.597) has the brucite (Mg(OH)2) structure in which the cobalt atoms are surrounded by six hydroxides. The blue form is more disordered, but its structure is not known for certain.
  • UsesCobalt(II) hydroxide is used as a drier for paints and varnishes and is added to lithographic printing inks to enhance their drying properties. Other applications are in the preparation of cobalt salts; as a catalyst; and in storage battery electrodes.
  • PreparationCobalt(II) hydroxide is obtained as a precipitate when an alkaline hydroxide is added to an aqueous solution of cobalt(II) salt:
    CoCl2 + 2NaOH → Co(OH)2 + 2NaCl
    Co(NO3)2 + 2NaOH → Co(OH)2 + 2NaNO3
  • ReactionsThermal decomposition to cobaltous oxide, CoO, occurs at 168°C in a vacuum.
    Cobalt(II) hydroxide is oxidized by air and other oxidizing agents, forming cobalt(III) hydroxide, Co(OH)3. Reactions with mineral acids produce corresponding Co2+ salts.
  • DescriptionThe addition of alkali metal hydroxides to solutions of cobalt(II) salts results in the precipitation of cobalt(II) hydroxide in either a blue or pink form depending upon the conditions. The pink form is the more stable of the two and is obtained when a suspension of the blue form is allowed to stand or is warmed. Cobalt(II) hydroxide is amphoteric, dissolving in alkalis to form blue solutions of the [Co(OH)4]2- ions. In the presence of alkali, suspensions of Co(OH) are oxidized by air to the brown CoO(OH), this oxidation being brought about rapidly by oxidants such as hypochlorite, bromine water or hydrogen peroxide. The pink Co(OH)2 (density 3.597) has the brucite (Mg(OH)2) structure in which the cobalt atoms are surrounded by six hydroxides. The blue form is more disordered, but its structure is not known for certain.
  • Chemical PropertiesRose-red powder.Soluble in acids and ammonium salt solutions; insoluble in water and alkalies.
  • UsesCobalt salts, paint and varnish driers, catalyst, storage-battery electrodes.
Cobalt(II) hydroxide Preparation Products And Raw materials
Cobalt(II) hydroxide(21041-93-0)Related Product Information
Cobalt(II) hydroxideSupplierMore
  • Company Name:J & K SCIENTIFIC LTD.
  • Tel:400-666-7788 010-82848833-
  • Email:jkinfo@jkchemical.com;market6@jkchemical.com
  •  
  • Company Name:Alfa Aesar
  • Tel:400-610-6006
  • Email:saleschina@alfa-asia.com
  •  
  • Company Name:Beijing dtftchem Technology Co., Ltd.
  • Tel:13651141086
  • Email:dtftchem@sina.com
  •  
  • Company Name:BeiJing Hwrk Chemicals Limted
  • Tel:18516978288 0757-86329057-
  • Email:sales.gd@hwrkchemical.com
  •  
  • Company Name:Energy Chemical
  • Tel:400-005-6266 021-58432009-
  • Email:sales8178@energy-chemical.com
  •