Thorianite

Formula : ThO2

Family: 
Oxides
Space group: 
Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: F m3m
Dana class: 
5.1.1.2 (5)Oxides Containing Uranium and Thorium (5.1) with a cation charge of 4+ (AO2) (5.1.1) Dana Group
High temperature: 
Medium to high temperature mineral.
Geological context: 
As primary mineral in pegmatite, and in carbonatite.

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
264.037 26.404 (Ref.: 95rob/hem) Robie R.A., and Hemingway B.S., 1995. Thermodynamic properties of minerals and related substances at 298.15 K and 1 Bar (105 Pascals) pressure and at higher temperatures. U.S. Geol. Survey Bull., 2131, 461 pp. -1169238 (Ref.: Internal calculation) -1226400 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p. 65.230 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p. 61.76 (Ref.: 91kna/kub) O. Knacke, O. Kubaschewski and K. Hesselmann: Thermochemical Properties of Inorganic Substances, Second Edition, (Springer-Verlag, 1991)
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.
71.29 7.22 -10.39 (Ref.: 91kna/kub) O. Knacke, O. Kubaschewski and K. Hesselmann: Thermochemical Properties of Inorganic Substances, Second Edition, (Springer-Verlag, 1991)
Reaction properties

Thorianite + 4H+ ⇌ Th+4 + 2H2O

298.15 K, 1 bar log10K: 1.76 ΔH°r:-113777 J·mol-1 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p.
T(°C) 0 25 60 100 150 200 250 300
log10K 3.61 1.76 -0.30 -2.14 -3.94 -5.40 -6.69 -7.91
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-565.835581 -0.092405 32187.788564 202.471055 -1227768.414717