Lanthanum hydroxide

Lanthanum hydroxide is Template:Chem, a hydroxide of the rare-earth element lanthanum.

Synthesis

Lanthanum hydroxide can be obtained by adding an alkali such as ammonia to aqueous solutions of lanthanum salts such as lanthanum nitrate. This produces a gel-like precipitate that can then be dried in air.

Template:Chem2

Alternatively, it can be produced by hydration reaction (addition of water) to lanthanum oxide.

Template:Chem2

Characteristics

Lanthanum hydroxide does not react much with alkaline substances, however is slightly soluble in acidic solution. In temperatures above 330 °C it decomposes into lanthanum oxide hydroxide (LaOOH), which upon further heating decomposes into lanthanum oxide (Template:Chem2):

Template:Chem2 $\underset{-H_{2}O}{\overset{330{}^{o}C}{\to }}$ LaOOH

2 LaOOH $\underset{-H_{2}O}{\overset{\mathrm{\Delta }}{\to }}$ Template:Chem2

Lanthanum hydroxide crystallizes in the hexagonal crystal system. Each lanthanum ion in the crystal structure is surrounded by nine hydroxide ions in a tricapped trigonal prism.

External links

• Template:Cite web
• External MSDS 1
• External MSDS 2
• Lanthanum Oxide MSDS

Template:Inorganic-compound-stub