Jarosite(K)

Formula : KFe3(SO4)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
500.811 160.260 (Ref.: 76men/sab) Menchetti S., Sabelli C. (1976) Neues Jb. Miner., Mh., H.9, 406-417 -3304989 (Ref.: 96abar/pal) Baron D. and Palmer C. D., 1996a. Solubility of KFe3(CrO4)2(OH)6 at 4-35C. Geochim. Cosmochim. Acta, 60, pp. 3815-3824. -3829600 (Ref.: 03dro/nav) Drouet C, Navrotsky A (2003) Synthesis, characterization and thermochemistry of K-Na-H3O jarosites. Geochim Cosmochim Acta 67:2063-2076 279.298 (Ref.: Internal calculation) 421.79 (Ref.: 03dro/nav) Drouet C, Navrotsky A (2003) Synthesis, characterization and thermochemistry of K-Na-H3O jarosites. Geochim Cosmochim Acta 67:2063-2076
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.
616.89 98.74 -199.60 (Ref.: 03dro/nav) Drouet C, Navrotsky A (2003) Synthesis, characterization and thermochemistry of K-Na-H3O jarosites. Geochim Cosmochim Acta 67:2063-2076
Reaction properties

Jarosite(K) + 6H+ ⇌ 3Fe+3 + K+ + 2SO4-2 + 6H2O

298.15 K, 1 bar log10K: -10.99 ΔH°r:-103200 J·mol-1 (Ref.: 03dro/nav) Drouet C, Navrotsky A (2003) Synthesis, characterization and thermochemistry of K-Na-H3O jarosites. Geochim Cosmochim Acta 67:2063-2076
T(°C) 0 25 60 100 150 200 250 300
log10K -9.50 -10.99 -13.09 -15.38 -18.23 -21.20 -24.55 -28.67
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-4198.908120 -0.680496 230053.894379 1522.260840 -13114957.188639