Nickel(II) hydroxide

Nickel(II) hydroxide
Identifiers
CAS number	12054-48-7 Y,  36897-37-7 (monohydrate)
PubChem	61534
ChemSpider	55452 Y
RTECS number	QR6480000
Jmol-3D images	Image 1
SMILES [Ni+2].[OH-].[OH-]
InChI InChI=1S/Ni.2H2O/h;2*1H2/q+2;;/p-2 Y Key: BFDHFSHZJLFAMC-UHFFFAOYSA-L Y InChI=1/Ni.2H2O/h;2*1H2/q+2;;/p-2 Key: BFDHFSHZJLFAMC-NUQVWONBAJ
Properties
Molecular formula	Ni(OH)2
Molar mass	92.708 g/mol (anhydrous) 110.72 g/mol (monohydrate)
Appearance	green crystals
Density	4.10 g/cm3
Melting point	230 °C (anhydrous, decomp)
Solubility in water	insoluble
Solubility	soluble in dilute acid, ammonia (monohydrate)
Structure
Crystal structure	hexagonal
Thermochemistry
Std enthalpy of formation ΔfHo298	-530.049 kJ/mol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

The test tube in the middle contains a precipitate of nickel(II) hydroxide

Nickel(II) hydroxide Ni(OH)₂ is an insoluble compound commonly used in rechargeable battery electrodes. When charged these electrodes form nickel(III) oxide-hydroxide. Nickel(II) hydroxide is a precipitate formed when the hexaaquanickel(II) ion is mixed with aqueous alkali. The mineralogical form is very rare and is called theophrastite.

See also

• Nickel-cadmium battery
• Nickel hydrogen battery
• Nickel metal hydride battery
• Nickel-iron battery

External links