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Nickel(II) sulfate

Nickel(II) Sulfate

General
Systematic name	Nickel(II) sulfate, hexahydrate
Molecular formula	NiSO₄^.6H₂O
Molar mass g/mol	262.85 g/mol (hexahydrate)
Appearance	Blue crystals (hexahydrate)
CAS number	[10101-97-0] (hexahydrate)
EINECS number	*
Properties
Density and phase	2.07 g/cm³ (hexahydrate)
Solubility in water	highly soluble
Solubility in ethanol	sparingly (hexahydrate)
Melting point	decomp. >100 °C
Structure
Coordination geometry	octahedral at Ni
Crystal structure	Monoclinic?
Thermodynamic data
Standard enthalpy of formation Δ_fH°_solid	* kJ/mol (anhyd form)
Standard molar entropy S°_solid	* J.K⁻¹.mol⁻¹ for the hexahydrate?
Safety data
MSDS	ScienceLab.com
NFPA 704	0 2 0
EU classification	not listed
Safety statements	22-36/37-60-61
Risk statements	22-40-42/43-50/53
RTECS number	QR9600000
Supplementary data page
Thermodynamic data	Phase behaviour Solid
Spectral data	UV
Related compounds
Other anions	Nickel(II) bromide Nickel(II) chloride
Other cations	Copper(II) sulfate Cobalt(II) sulfate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Nickel(II) sulfate or just nickel sulfate, usually refers to the chemical compound with the formula NiSO₄^.6H₂O. This blue salt is a common laboratory source of nickel. It also occurs as the rare mineral Retgersite. The anhydrous salt, NiSO₄, a high melting solid, is also known but is less commonly encountered. These nickel(II) compounds are paramagnetic.

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1 Synthesis and structure
2 Coordination chemistry
3 Applications
4 Safety
5 References

Synthesis and structure

Dissolution of nickel hydroxide in sulfuric acid followed by evaporation produces crystals of this salt or the corresponding heptahydrate. X-ray crystallography measurements show that NiSO₄^.6H₂O consists of octahedral [Ni(H₂O)₆]²⁺ ions. These ions in turn are hydrogen bonded to sulfate ions.^[1] Dissolution of the salt in water gives solutions containing the ion [Ni(H₂O)₆]²⁺.

Coordination chemistry

NiSO₄^.6H₂O and related hydrates react with ammonia to give [Ni(NH₃)₆]SO₄ and with ethylenediamine to give [Ni(H₂NCH₂CH₂NH₂)₃]SO₄. The latter is occasionally used as a calibrant for magnetic susceptibility measurements because it has no tendency to hydrate.

Applications

NiSO₄^.6H₂O in combination with boric acid or nickel(II) chloride is used in some electroplating baths.

Safety

Nickel salts are considered carcinogenic.

References

^ Wells, A. F. (1984). Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.

Categories: Nickel compounds | Sulfates | IARC Group 1 carcinogens | Coordination compounds

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Nickel(II)_sulfate". A list of authors is available in Wikipedia.