Cobalt(II) nitrate
Cobalt nitrate is the inorganic compound with the formula Co(NO3)2.xH2O. It is cobalt(II)'s salt. The most common form is the hexahydrate Co(NO3)2·6H2O, which is a red-brown deliquescent salt that is soluble in water and other polar solvents.[2]
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| Other names
Cobaltous nitrate Nitric acid, cobalt(2+) salt | |
| Identifiers | |
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| ECHA InfoCard | 100.030.353  |
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| UNII | |
| UN number | 1477 |
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| Properties | |
| 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 (212 °F; 373 K) decomposes (anhydrous) 55 °C (hexahydrate) |
| Boiling point | 100 to 105 °C (212 to 221 °F; 373 to 378 K) decomposes (anhydrous) 74 °C, decomposes (hexahydrate) |
| anhydrous:[1] 84.03 g/100 mL (0 °C) 334.9 g/100 mL (90 °C) soluble (anhydrous) | |
| Solubility | soluble in alcohol, acetone, ethanol, ammonia (hexahydrate), methanol 2.1 g/100 mL |
| Structure | |
| monoclinic (hexahydrate) | |
| Hazards | |
| Safety data sheet | Cobalt (II) Nitrate MSDS |
| GHS pictograms |   |
| GHS Signal word | Danger |
| H317, H334, H341, H350, H360, H400, H410 | |
| P201, P202, P261, P272, P273, P280, P281, P285, P302+352, P304+341, P308+313, P321, P333+313, P342+311, P363, P391, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
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 otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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| Infobox references | |
Composition and structures
As well as the anhydrous compound Co(NO3)2, several hydrates of cobalt(II) nitrate exist. These hydrates have the 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.[3] 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.[4] Above 55 °C, the hexahydrate converts to the trihydrate and at higher temperatures to the monohydrate.[2]
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Uses
It is commonly reduced to metallic high purity cobalt.[2] It can be absorbed on to various catalyst supports for use in Fischer-Tropsch catalysis.[5] It is used in the preparation of dyes and inks.[6]
Production
The hexahydrate is prepared treating metallic cobalt or one of its oxides, hydroxides, or carbonate with nitric acid:
- Co + 4 HNO3 + 4 H2O → Co(H2O)6(NO3)2 + 2 NO2
- CoO + 2 HNO3 + 5 H2O → Co(H2O)6(NO3)2
- CoCO3 + 2 HNO3 + 5 H2O → Co(H2O)6(NO3)2 + CO2
References
- Perrys' Chem Eng Handbook, 7th Ed
- John Dallas Donaldson, Detmar Beyersmann, "Cobalt and Cobalt Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a07_281.pub2
- 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.
- Prelesnik, P. V.; Gabela, F.; Ribar, B.; Krstanovic, I. (1973). "Hexaaquacobalt(II) nitrate". Cryst. Struct. Commun. 2 (4): 581–583.
- Ernst B, Libs S, Chaumette P, Kiennemann A. Appl. Catal. A 186 (1-2): 145-168 1999
- 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(NO 3)− 4 |
RONO2 | NO− 3 NH4NO3 |
HOONO2 | FNO3 | Ne | ||||||||||
| NaNO3 | Mg(NO3)2 | Al(NO3)3 | Si | P | S | ClONO2 | Ar | ||||||||||
| KNO3 | Ca(NO3)2 | Sc(NO3)3 | Ti(NO3)4 | VO(NO3)3 | Cr(NO3)3 | Mn(NO3)2 | Fe(NO3)2 Fe(NO3)3 |
Co(NO3)2 Co(NO3)3 |
Ni(NO3)2 | CuNO3 Cu(NO3)2 |
Zn(NO3)2 | Ga(NO3)3 | Ge | As | Se | Br | Kr |
| RbNO3 | Sr(NO3)2 | Y(NO3)3 | Zr(NO3)4 | Nb | Mo | Tc | Ru(NO3)3 | Rh(NO3)3 | Pd(NO3)2 Pd(NO3)4 |
AgNO3 Ag(NO3)2 |
Cd(NO3)2 | In(NO3)3 | Sn | Sb(NO3)3 | Te | INO3 | Xe(NO3)2 |
| CsNO3 | Ba(NO3)2 | Hf(NO3)4 | Ta | W | Re | Os | Ir | Pt(NO3)2 Pt(NO3)4 |
Au(NO3)3 | Hg2(NO3)2 Hg(NO3)2 |
TlNO3 Tl(NO3)3 |
Pb(NO3)2 | Bi(NO3)3 BiO(NO3) |
Po(NO3)4 | At | Rn | |
| FrNO3 | Ra(NO3)2 | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og | |
| ↓ | |||||||||||||||||
| La(NO3)3 | Ce(NO3)3 Ce(NO3)4 |
Pr(NO3)3 | Nd(NO3)3 | Pm(NO3)3 | Sm(NO3)3 | Eu(NO3)3 | Gd(NO3)3 | Tb(NO3)3 | Dy(NO3)3 | Ho(NO3)3 | Er(NO3)3 | Tm(NO3)3 | Yb(NO3)3 | Lu(NO3)3 | |||
| Ac(NO3)3 | Th(NO3)4 | PaO2(NO3)3 | UO2(NO3)2 | Np(NO3)4 | Pu(NO3)4 | Am(NO3)3 | Cm(NO3)3 | Bk | Cf | Es | Fm | Md | No | Lr | |||