Nickel(II) nitrate hexahydrate

Description

Nickel (II) nitrate hexahydrate appears as green crystals and substantially soluble in water. It is stable, a strong oxidiser, and incompatible with reducing agents. It has wide industrial applications in nickel plating as catalysts and is indirectly associated with other industries of nickel alloy manufacturers, nickel miners, smelters and refiners, nickel platers, and exposure to alloys, for example, in coinage.

Chemical properties

Green crystal

The Uses of Nickel(II) nitrate hexahydrate

Nickel plating, manufacturing of ceramic colorsNickel(II) nitrate hexahydrate is used as a precursor in the manufacturing of other nickel salts and supported nickel catalysts. It finds use as a catalyst in organic synthesis. Further it is used in electroplating and as a mordent in textile dyeing. It is a precursor for preparing nickel sulfide-reduced graphene oxide (RGO) composite powders with high initial capacities and good cycling performance. It can be employed in the preparation of nickel and nickel oxide nanocrystals impregnated O-MWCNTs (oxygen-functionalized multi-walled carbon nanotubes) with potential applications in semiconductor industries. It finds use in improving cycling stability ad rate capability of Li2MnO3.

The Uses of Nickel(II) nitrate hexahydrate

Nickel(II) nitrate hexahydrate may be used as a precursor for the synthesis of [Ni_1/3Co_1/3Mn_1/3]O₂ powders, Ni(II) oxide aerogels and crystalline nickel complexes, [Ni(C₆H₇N₃O)₂(NO₃)₂] and [Ni(C₆H₇N₃O)₃](NO₃)₂·H₂O.

Preparation

Emerald green crystals of the hexahydrate Ni(N03)2?6H20 crystallize from aqueous solutions at room temperature. These are isomorphous with the corresponding cobalt(II) salt containing the regular octahedral [Ni(H20)6]2+ ions with Ni-O distances = 2.03 A. The tetrahydrate crystallize above 54° and the dihydrate above 85.4°. The pale green anhydrous nitrate can be obtained by dehydration of the hydrate with dinitrogen pentoxide in fuming nitric acid or by the liquid phase reaction of dinitrogen tetroxide with nickel carbonyl [the gas phase reaction gives the nitrite Ni(N02)2]
Ni(CO)4+2N2O4 -* Ni(N03)2+2NO+4CO
The first product of this latter rather violent reaction is the adduct Ni(NO3)2N2O4 from which the nitrogen tetroxide is removed by heating in vacuo. It can also be prepared by the reaction of dinitrogen tetroxide-ethyl acetate mixtures with nickel(II) chloride. The infrared spectrum shows it to be a typical covalent nitrate. It is involatile and decomposes upon heating in nitrogen to give the nitrite Ni(NO2)2 above 260°.

General Description

Nickel(II) nitrate hexahydrate (Ni(NO₃)₂.6H₂O) is a hydrated nickel(II) salt. Its thermal degradation has been investigated by thermogravimetric methods under quasi-isothermal conditions.

Safety Profile

Confirmed carcinogen. Moderately toxic by ingestion. When heated to decomposition it emits toxic fumes of NOx. See also NICKEL(II) NITRATE.

Purification Methods

Crystallise it from water (3.3g/mL) by partial evaporation in a desiccator. Store it in a desiccator as it is deliquescent.