Goyazite

Formula : SrAl3(PO4)2(OH)5:H2O

Family: 
Phosphates
Space group: 
Trigonal - Hexagonal ScalenohedralH-M Symbol (3 2/m) Space Group: R 3m

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
461.559 142.120 (Ref.: 04gab/vie) Gaboreau S. and Vieillard Ph. (2004). Prediction of Gibbs free energies of formation of minerals of the alunite supergroup. Geochimica and Cosmochimica Acta, 68, 3307-3316 -5627800 (Ref.: 89sch/her) Schwab R. G., Herold H., Costa M. L. D., and Oliveira N. P. (1989) The formation of aluminous phosphates through lateritic weathering of rocks. Weathering 2, 369-386. -6152092 (Ref.: Internal calculation) 357.730 (Ref.: 04gab/vie) Gaboreau S. and Vieillard Ph. (2004). Prediction of Gibbs free energies of formation of minerals of the alunite supergroup. Geochimica and Cosmochimica Acta, 68, 3307-3316 103.04 (Ref.: 04gab/vie) Gaboreau S. and Vieillard Ph. (2004). Prediction of Gibbs free energies of formation of minerals of the alunite supergroup. Geochimica and Cosmochimica Acta, 68, 3307-3316
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.
112.27 63.98 -25.16 (Ref.: 04gab/vie) Gaboreau S. and Vieillard Ph. (2004). Prediction of Gibbs free energies of formation of minerals of the alunite supergroup. Geochimica and Cosmochimica Acta, 68, 3307-3316
Reaction properties

Goyazite + 9H+ ⇌ 3Al+3 + 2H2PO4- + Sr+2 + 6H2O

298.15 K, 1 bar log10K: 16.85 ΔH°r:-334188 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K 22.17 16.85 10.67 4.99 -0.77 -5.63 -10.07 -14.54
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-3052.710301 -0.477858 177046.566032 1098.615506 -8910512.479751