Gallium hydroxide

Crystal structure
	__ Ga 3+ __ OH -
General
Surname	Gallium hydroxide
other names	Gallium trihydroxide; Gallium (III) hydroxide;
Ratio formula	Ga (OH) 3
Brief description	colorless amorphous mass or crystalline substance
External identifiers / databases
EC number	234-687-5
ECHA InfoCard	100,031,521
PubChem	10154045
Wikidata	Q419661
properties
Molar mass	120.74 g mol −1
Physical state	firmly
density	3.84 g cm −3
solubility	soluble in dilute mineral acids
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Gallium hydroxide is a chemical compound of gallium from the group of hydroxides .

Occurrence

Gallium hydroxide occurs naturally as the mineral söhngeit .

Extraction and presentation

Gallium hydroxide is formed during the neutralization of gallium (III) salt solutions . Gallium hydroxide hydrate is a by- product of aluminum production .

{\ displaystyle {\ ce {GaCl3 + 3 NH4OH -> Ga (OH) 3 v + 3 NH4Cl}}}

properties

Gallium hydroxide occurs either as a colorless amorphous mass or as a colorless orthorhombic and pseudocubic crystalline substance. In addition to gallium hydroxide, gallium (III) oxide monohydrate (GaO (OH) or Ga ₂ O ₃ • H ₂ O) can also be regarded as a further hydroxide of gallium ( gallium oxide hydroxide ), which occurs when gallium hydroxide is heated for a long time at around 170 ° C , by heating to 900 ° C at 50 kbar under hydrothermal conditions or slowly by aging . When heated above 500 ° C it decomposes with the formation of gallium (III) oxide.

{\ displaystyle \ mathrm {2 \ Ga (OH) _ {3} {\ xrightarrow {\ triangle}} Ga_ {2} O_ {3} +3 \ H_ {2} O \ uparrow}}

Gallium hydroxide crystallizes in the orthorhombic crystal system , space group Pmn 2 ₁ (space group no. 31) , with the lattice parameters a = 7.487 Å , b = 7.438 Å and c = 7.496 Å. Each gallium atom is coordinated octahedral by six hydroxide ions, each hydroxide ion binds to two gallium ions. Template: room group / 31

use

By reaction with hydrogen sulfide can gallium (III) sulfide are obtained.

{\ displaystyle \ mathrm {2 \ Ga (OH) _ {3} +3 \ H_ {2} S \ longrightarrow Ga_ {2} S_ {3} +6 \ H_ {2} O}}

Individual evidence

↑ ^a ^b ^c ^d Kirk-Othmer Encyclopedia of Chemical Technology: Gallium and Gallium Compounds ( Memento of April 27, 2012 in the Internet Archive )
↑ ^a ^b Handbookofmineralogy: Söhngeit (PDF; 70 kB)
↑ Jean D'Ans, Ellen Lax; Paperback for chemists and physicists: Volume 3, p. 464; ISBN 978-3540600350
↑ ^a ^b Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 855.
↑ Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of gallium trihydroxide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), which was accessed on May 26, 2020, is reproduced from a self-classification by the distributor .
^ Mineralienatlas: Söhngeit
^ ^A ^b A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1196.
↑ JD Scott: Crystal structure of a new mineral, sohngeite. In: American Mineralogist , 56, 1871, p. 355.
↑ Georg Brauer , with the collaboration of Marianne Baudler a . a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 857 .

[KO-1] Kirk-Othmer Encyclopedia of Chemical Technology: Gallium and Gallium Compounds ( Memento of April 27, 2012 in the Internet Archive )

[HboM-2] Handbookofmineralogy: Söhngeit (PDF; 70 kB)

[TC-3] Jean D'Ans, Ellen Lax; Paperback for chemists and physicists: Volume 3, p. 464; ISBN 978-3540600350

[brauer-4] Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 855.

[5] Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of gallium trihydroxide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), which was accessed on May 26, 2020, is reproduced from a self-classification by the distributor .

[6] Mineralienatlas: Söhngeit

[HoWi-7] A ^b A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1196.

[8] JD Scott: Crystal structure of a new mineral, sohngeite. In: American Mineralogist , 56, 1871, p. 355.

[Bibbrauer-9] Georg Brauer , with the collaboration of Marianne Baudler a . a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 857 .