Cobalt(II) nitrate

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Cobalt(II) nitrate
Cobalt (II) Nitrate Hexahydrate Sample
Identifiers
CAS number 10141-05-6 YesY
10026-22-9 (hexahydrate)
PubChem 25000
ChemSpider 23369 YesY
UNII 65W79BFD5V YesY
EC number 233-402-1
RTECS number GG1109000
Jmol-3D images Image 1
Properties
Molecular formula Co(NO3)2
Molar mass 182.943 g/mol (anhydrous)
291.03 g/mol (hexahydrate)
Appearance pale red powder (anhydrous)
red crystalline (hexahydrate)
Odor odorless (hexahydrate)
Density 2.49 g/cm3 (anhydrous)
1.87 g/cm3 (hexahydrate)
Melting point 100 °C, decomp (anhydrous)
55 °C (hexahydrate)
Boiling point 100–105 °C, decomp (hexahydrate)
74 °C, decomp (hexahydrate)
Solubility in water hexahydrate: 134 g/100 mL (0 °C)
103.8 g/100 mL (25 °C)
soluble (anhydrous)
Solubility soluble in alcohol, acetone, ethanol, ammonia (hexahydrate)
Structure
Coordination
geometry
monoclinic (hexahydrate)
Hazards
MSDS Cobalt (II) Nitrate MSDS
EU Index 027-009-00-2
EU classification Carc. Cat. 2
Muta. Cat. 3
Repr. Cat. 2
Toxic (T)
Dangerous for the environment (N)
R-phrases R49, R60, R42/43, R68, R50/53
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazard OX: Oxidizer. E.g., potassium perchlorateNFPA 704 four-colored diamond
LD50 434 mg/kg; rat, oral (anhydrous)
691 mg/kg; rat, oral (hexahydrate)
Related compounds
Other anions Cobalt(II) sulfate
Cobalt(II) chloride
Cobalt oxalate
Other cations Iron(III) nitrate
Nickel(II) nitrate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Cobalt nitrate is the inorganic cobalt(II) salt of nitric acid, often with various amounts of water. It is more commonly found as a hexahydrate, Co(NO3)2·6H2O, which is a red-brown deliquescent salt that is soluble in water and other polar solvents.

Preparation[edit]

Cobalt(II) nitrate is formed by the interaction of cobalt oxide, hydroxide or carbonate with nitric acid.

Composition and structures[edit]

As well as the anhydrous compound Co(NO3)2, there are several hydrates of cobalt(II) nitrate. The various degrees of hydration can be summarised by the general chemical formula Co(NO3)2·nH2O, where n = 0, 2, 4, 6.

Anhydrous cobalt(II) nitrate adopts a three-dimensional polymeric network structure, with each cobalt(II) atom approximately octahedrally coordinated by six oxygen atoms, each from a different nitrate ion. Each nitrate ion coordinates to three cobalts.[1] The dihydrate is a two-dimensional polymer, with nitrate bridges between Co(II) centres and hydrogen bonding holding the layers together. The tetrahydrate consists of discrete, octahedral [(H2O)4Co(NO3)2] molecules. The hexahydrate is better described as hexaaquacobalt(II) nitrate, [Co(OH2)6][NO3]2, as it consists of discrete [Co(OH2)6]2+ and [NO3] ions.[2]

Cobalt(II)-nitrate-xtal-2002-CM-3D-SF.png Cobalt(II)-nitrate-dihydrate-xtal-1976-CM-3D-balls.png Cobalt(II)-nitrate-tetrahydrate-xtal-1975-CM-3D-balls.png Hexaaquacobalt(II)-nitrate-xtal-1973-unit-cell-CM-3D-balls.png
Co(NO3)2
Co(NO3)2·2H2O
Co(NO3)2·4H2O
Co(NO3)2·6H2O

Uses[edit]

It is commonly reduced to metallic cobalt or precipitated on various substrates for Fischer-Tropsch catalysis.[3]

Production[edit]

It is derived from reacting metallic cobalt or one of its oxides, hydroxides, or carbonate with nitric acid. It is commonly used in dyes and inks.[4]

CoCO3 + 2 HNO3 + 5 H2O → Co(NO3)2(H2O)6 + CO2

Above 55 °C, it dehydrates to the trihydrate and at higher temperatures to the monohydrate.

References[edit]

  1. ^ Tikhomirov, G. A.; Znamenkov, K. O.; Morozov, I. V.; Kemnitz, E.; Troyanov, S. I. (2002). "Anhydrous Nitrates and Nitrosonium Nitratometallates of Manganese and Cobalt, M(NO3)2, NO[Mn(NO3)3], and (NO)2[Co(NO3)4]: Synthesis and Crystal Structure". Z. anorg. allg. Chem. 628 (1): 269–273. doi:10.1002/1521-3749(200201)628:1<269::AID-ZAAC269>3.0.CO;2-P. 
  2. ^ Prelesnik, P. V.; Gabela, F.; Ribar, B.; Krstanovic, I. (1973). Cryst. Struct. Commun. 2: 581–583. 
  3. ^ Ernst B, Libs S, Chaumette P, Kiennemann A. Appl. Catal. A 186 (1-2): 145-168 1999
  4. ^ Lewis, Richard J., Sr. (2002). Hawley's Condensed Chemical Dictionary (14th Edition). John Wiley & Sons. http://www.knovel.com/knovel2/Toc.jsp?BookID=704&VerticalID=0
HNO3 He
LiNO3 Be(NO3)2 B C (NH4)2NO3 O FNO3 Ne
NaNO3 Mg(NO3)2 Al(NO3)3 Si P S ClONO2 Ar
KNO3 Ca(NO3)2 Sc(NO3)3 Ti V Cr(NO3)3 Mn(NO3)2 Fe(NO3)3 Co(NO3)2,
Co(NO3)3
Ni(NO3)2 Cu(NO3)2 Zn(NO3)2 Ga(NO3)3 Ge As Se Br Kr
RbNO3 Sr(NO3)2 Y Zr Nb Mo Tc Ru Rh Pd(NO3)2 AgNO3 Cd(NO3)2 In Sn Sb Te I Xe
CsNO3 Ba(NO3)2   Hf Ta W Re Os Ir Pt Au Hg2(NO3)2,
Hg(NO3)2
Tl(NO3)3 Pb(NO3)2 Bi(NO3)2 Po At Rn
Fr Ra   Rf Db Sg Bh Hs Mt Ds Rg Cn Uut Fl Uup Lv Uus Uuo
La Ce(NO3)x Pr Nd Pm Sm Eu Gd(NO3)3 Tb Dy Ho Er Tm Yb Lu
Ac Th Pa UO2(NO3)2 Np Pu Am Cm Bk Cf Es Fm Md No Lr