Jarosite(Cr)

Formula : KFe3(CrO4)2(OH)6

Family: 
Alunite
Space group: 
Trigonal - Rhombohedral or Pyramidal HM symbol (3 or -3) Space Group: R 3
Dana class: 
30.2.5.1VI- 30 Anhydrous Sulfates Containing Hydroxyl or Halogen ; 30.2 Anhydrous Sulfates Containing Hydroxyl or Halogen where (A B)2 XO4 Zq ; 30.2.5 Alunite Group (Jarosite Subgroup)

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
540.611 -3305054 (Ref.: Internal calculation) -3762500 (Ref.: 96bbar/pal) Baron D. and Palmer C. D. (1996b) Solubility of jarosite at 4-35C. Geochim. Cosmochim. Acta 60, 185-195. 487.700 (Ref.: 96bbar/pal) Baron D. and Palmer C. D. (1996b) Solubility of jarosite at 4-35C. Geochim. Cosmochim. Acta 60, 185-195.
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.
Reaction properties

Jarosite(Cr) + 6H+ ⇌ 2CrO4-2 + 3Fe+3 + K+ + 6H2O

298.15 K, 1 bar log10K: -17.94 ΔH°r:-109620 J·mol-1 (Ref.: 96bbar/pal) Baron D. and Palmer C. D. (1996b) Solubility of jarosite at 4-35C. Geochim. Cosmochim. Acta 60, 185-195.
T(°C) 0 25 60 100 150 200 250 300
log10K -16.26 -17.94 -20.02 -22.01 -24.18 -26.30 -28.67 -31.74
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-4440.654501 -0.683091 243494.722525 1601.337578 -13575564.782221