As(element)

Formula : As

Family: 
Element
Space group: 
Trigonal - Hexagonal Scalenohedral HM symbol (-3 2/m) Space Group: R 3m
Dana class: 
1.3.1.1I - 1 Native Elements ; 1.3 Native Elements with semi-metallic and non-metallic elements ; 1.3.1 Arsenic group
High temperature: 
Low and high temperature stability.
Geological context: 
Hydrothermal and sedimentary to igneous mineral.

Dernière mise à jour le 25.01.2021

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
 V°
cm3·mol-1
 ΔGºf
J·mol-1
 ΔHºf
J·mol-1
 Sº
J·mol-1·k-1
 CP
J·mol-1·K-1
74.922 12.960 (Ref.: 96pok/gou) Pokrovski G., Gout R., Schott J., Zotov A. and Harrichoury J.C., 1996. Thermodynamic properties and stoichiometry of As (III) hydroxide complexes at hydrothermal conditions. Geochimica et Cosmochimica Acta, 60, 737-749 0 (Ref.: By convention) 0 (Ref.: Internal calculation) 35.690 (Ref.: 73hul/des) Hultgren R., Desai P. D., Hawkins D. T., Gleiser M., Kelly K. K. and Wagman D. (1973) Selected Values of the Thermodynamic Properties of the Elements. Metals Park, Ohio, AMS. 24.66 (Ref.: 73hul/des) Hultgren R., Desai P. D., Hawkins D. T., Gleiser M., Kelly K. K. and Wagman D. (1973) Selected Values of the Thermodynamic Properties of the Elements. Metals Park, Ohio, AMS.
CP(T) = a + b·T + ·c·T-2 (T in Kelvin)
a
J·mol-1·K-1
 b * 103
J·mol-1·K-2
 c * 10-5
J·K·mol-1
 Maier Kelley Ref.
23.71 4.85 -0.44 (Ref.: 73hul/des) Hultgren R., Desai P. D., Hawkins D. T., Gleiser M., Kelly K. K. and Wagman D. (1973) Selected Values of the Thermodynamic Properties of the Elements. Metals Park, Ohio, AMS.
Reaction properties

As(element) + 1.5H2O ⇌ AsH3 + 0.75O2

298.15 K, 1 bar log10K: -81.94 ΔH°r:487814 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K -89.71 -81.94 -72.90 -64.53 -56.18 -49.48 -43.97 -39.31
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
283.841362 0.044721 -43128.642046 -100.584384 1282715.668316