Nickel(II) carbonate
Encyclopedia
Nickel carbonate describes one or a mixture of inorganic compounds containing nickel and carbonate
. From the industrial perspective, the most important nickel carbonate is basic nickel carbonate with the formula Ni4CO3(OH)6(H2O)4. Simpler carbonates, ones more likely encountered in the laboratory, are NiCO3 and its hexahydrate. All are paramagnetic green solid consisting of Ni
2+ cations. The basic carbonate is an intermediate in the hydrometallurgical purification
of nickel from its ores and is used in electroplating of Ni. Nickel carbonates are used in some ceramic applications and as precursors to catalysts.
Nickel carbonates are hydrolyzed
upon contact with by aqueous acids to give solutions containing the ion [Ni(H2O)6]2+, liberating water and carbon dioxide
in the process. Calcining (heating to drive off CO2 and water) of these carbonates gives NiO
, shown here with anhydrous nickel carbonate:
The nature of the resulting oxide depends on the nature of the precursor. The oxide obtained from the basic carbonate is often most useful for catalysis
.
Basic nickel carbonate can be made by treating solutions of nickel sulfate with sodium carbonate
, shown here for the basic carbonate:
The hydrated carbonate has been prepared by electrolytic oxidation of nickel in the presence of carbon dioxide:
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
. From the industrial perspective, the most important nickel carbonate is basic nickel carbonate with the formula Ni4CO3(OH)6(H2O)4. Simpler carbonates, ones more likely encountered in the laboratory, are NiCO3 and its hexahydrate. All are paramagnetic green solid consisting of Ni
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
2+ cations. The basic carbonate is an intermediate in the hydrometallurgical purification
Hydrometallurgy
Hydrometallurgy is part of the field of extractive metallurgy involving the use of aqueous chemistry for the recovery of metals from ores, concentrates, and recycled or residual materials...
of nickel from its ores and is used in electroplating of Ni. Nickel carbonates are used in some ceramic applications and as precursors to catalysts.
Nickel carbonates are hydrolyzed
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
upon contact with by aqueous acids to give solutions containing the ion [Ni(H2O)6]2+, liberating water and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
in the process. Calcining (heating to drive off CO2 and water) of these carbonates gives NiO
Nickel oxide
Nickel oxide may refer to:* Nickel oxide, NiO, green, well-characterised oxide* Nickel oxide, Ni2O3, black, not well-characterised oxide...
, shown here with anhydrous nickel carbonate:
- NiCO3 → NiO + CO2
The nature of the resulting oxide depends on the nature of the precursor. The oxide obtained from the basic carbonate is often most useful for catalysis
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
.
Basic nickel carbonate can be made by treating solutions of nickel sulfate with sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...
, shown here for the basic carbonate:
- 4 Ni2+ + Na2CO3 + 6 OH- + 4 H2O → Ni4CO3(OH)6(H2O)4 + 2 Na+
The hydrated carbonate has been prepared by electrolytic oxidation of nickel in the presence of carbon dioxide:
- Ni + O + CO2 + 6 H2O → NiCO3(H2O)4