Aluminium arsenate

Aluminium arsenate
Names
Other names
Aluminum arsenate
Identifiers
13462-91-4 Yes
Jmol-3D images Image
PubChem 57351442
Properties
AlAsO4
Molar mass 165.901 g/mol
Appearance white crystals
Density 3.25 g/cm3
Melting point 1,000 °C (1,830 °F; 1,270 K)
insoluble
1.596
Structure
Crystal structure hexagonal
Thermochemistry
145.6 J/mol K
Std enthalpy of
formation (ΔfHo298)
 -1431.1 kJ/mol
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Aluminium arsenate is a inorganic compound with the formula AlAsO4.[1] It is most commonly found as an octahydrate. It is a colourless solid that is produced by the reaction between sodium arsenate and a soluble aluminium salt. Aluminium arsenate occurs naturally as the mineral mansfieldite.[2] A synthetic hydrate of aluminium arsenate is produced by hydrothermal method. with the formulation, Al2O3.3As2O5.10H2O.[3]
Modification of aluminium orthoarsenate was carried out by heating different samples to different temperatures.Both amorphous and crystalline forms were obtained.[4] The solubility product was determined to be 10−18.06. for Aluminium arsenate of formula AlAsO4.3.5H2O[5] Like gallium arsenate and boron arsenate, it adopts the α-quartz-type structure. The high pressure form has a rutile-type structure in which aluminium and arsenic are six-coordinate.

References

  1. ↑ Aluminum arsenate at Chemister
  2. ↑ Chemistry of Arsenic, Antimony, and Bismuth, Edited by N. C. Norman. page 131,
  3. ↑ http://www.minsocam.org/ammin/AM39/AM39_1005.pdf
  4. ↑ B. Sharan "A new modification of aluminum ortho-arsenate" Acta Cryst. 1959, vol. 12, 948-949. {{doi:10.1107/S0365110X59002729}}
  5. ↑ Fernando L. Pantuzzo, Luciano R.G. Santos, Virginia S.T. Ciminelli "Solubility-product constant of an amorphous aluminum-arsenate phase (AlAsO4·3.5H2O) AT 25 °C" Hydrometallurgy Volumes 2014, 144–145, Pages 63–68. doi:10.1016/j.hydromet.2014.01.001