- Zinc hydroxide
Chembox new
Name = Zinc hydroxide
OtherNames =
Section1 = Chembox Identifiers
CASNo = 20427-58-1
Section2 = Chembox Properties
Formula = Zn(OH)2
MolarMass = 99.39 g/mol
Appearance = white powder
Density = 3.053 g/cm3, solid
Solubility = Ksp = 4.5 x 10^-17
MeltingPt = 125°C (decomposition)
BoilingPt =
Section7 = Chembox Hazards
EUClass = not listed
NFPA-H = 3
NFPA-R = 0
NFPA-F = 0Zinc hydroxide Zn(OH)2 is an
inorganic chemical compound . It also occurs naturally as 3 rare minerals: wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal).It is unusual in that, like
zinc oxide , it isamphoteric . Thus it will dissolve readily in a dilute solution of astrong acid , such asHCl , and also in a solution ofsodium hydroxide .It can be prepared by adding sodium hydroxide solution, but not in excess, to a solution of any zinc salt. A white precipitate will be seen:Zn2+ + 2OH- → Zn(OH)2.
If excess sodium hydroxide is added, the precipitate of zinc hydroxide will dissolve, forming a colorless solution of
zincate ion : Zn(OH)2 + 2OH- → Zn(OH)42-. This property can be used as a test for zinc ions in solution, but it is not exclusive, since aluminum and lead compounds behave in a very similar manner.One major use is as an absorbent in
surgical dressings .References
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