Nickel nitrate is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

Ni(NO₃)₂ or any

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

thereof. The

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

form is not commonly encountered, thus "nickel nitrate" usually refers to nickel(II) nitrate

hexahydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

. The formula for this species is written in two ways: Ni(NO₃)₂^.6H₂O and, more descriptively i(H₂O)₆NO₃)₂. The latter formula indicates that the

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

(II) center is surrounded by six water molecules in this hydrated salt. In the hexahydrate, the

nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...

anions are not bonded to nickel. Also known are three other hydrates: Ni(NO₃)₂^.9H₂O, Ni(NO₃)₂^.4H₂O, and Ni(NO₃)₂^.2H₂O. Anhydrous Ni(NO₃)₂ is also known. It is prepared by the reaction of nickel oxide with nitric acid: : NiO + 2 HNO₃ + 5 H₂O → Ni(NO₃)₂^.6H₂O The anhydrous nickel nitrate is typically not prepared by the heating the hydrates. Rather is generated by reaction of hydrates with

dinitrogen pentoxide Dinitrogen pentoxide is the chemical compound with the formula , also known as nitrogen pentoxide or nitric anhydride. It is one of the binary nitrogen oxides, a family of compounds that only contain nitrogen and oxygen. It exists as colourless ...

or of

nickel carbonyl Nickel carbonyl (IUPAC name: tetracarbonylnickel) is a nickel(0) organometallic compound with the formula Ni(CO)4. This colorless liquid is the principal carbonyl of nickel. It is an intermediate in the Mond process for producing very high-pur ...

with

dinitrogen tetroxide Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium ...

: : Ni(CO)₄ + 2 N₂O₄ → Ni(NO₃)₂ + 2 NO + 4 CO The hydrated nitrate is often used as a precursor to supported nickel catalysts.

Structure

Nickel(II) compounds with oxygenated ligands often feature octahedral coordination geometry. Two polymorphs of the tetrahydrate Ni(NO₃)₂^.4H₂O have been crystallized. In one the monodentate nitrate ligands are trans while in the other they are cis.

Safety

Like other nitrates, nickel nitrate is

oxidizing Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

. It is also irritating to the eyes, skin and, upon inhalation of the dust,

respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa. Air is breathed in through the nose to th ...

. It may cause skin

allergy Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

. Nickel nitrate is a

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...

, along with most other nickel compounds. The nickel ion is also toxic to aquatic organisms.

Uses

Nickel(II) nitrate is primarily used in

electrotyping Electrotyping (also galvanoplasty) is a chemical method for forming metal parts that exactly reproduce a model. The method was invented by Moritz von Jacobi Moritz Hermann or Boris Semyonovich (von) Jacobi (russian: Борис Семёнови ...

and

electroplating Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...

of metallic nickel.

References

{{nitrates Nickel compounds Nitrates IARC Group 1 carcinogens Oxidizing agents