Realgar

Formula : AsS

Family: 
Sulfides
Space group: 
Monoclinic - Prismatic HM symbol (2/m) Space Group: P 21/n
Dana class: 
2.8.22.1II- 2 Sulfide Minerals ; 2.8 Sulfides - Including Selenides and Tellurides where Am Bn Xp, with (m+n):p=1:1 ; 2.8.22

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
106.988 29.800 (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 -30519 (Ref.: 13bla/las) Blanc P., Lassin A. (2013) - Thermoddem : Selection de proprietes thermodynamiques pour les principales especes aqueuses et minerales porteuses d'arsenic. Rapport final. BRGM/RP-62585-FR. 29 p., 5 fig., 3 tabl. -32417 (Ref.: Internal calculation) 61.379 (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 60.70 (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
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.
54.14 -0.06 5.84 (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
Reaction properties

Realgar + 0.25O2 + 2.5H2O ⇌ H2AsO3- + HS- + 2H+

298.15 K, 1 bar log10K: -7.80 ΔH°r:24594 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K -8.24 -7.80 -7.41 -7.19 -7.16 -7.35 -7.75 -8.45
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-1003.454295 -0.166315 52749.123518 365.458402 -3198647.607419