Farringtonite

Formula : Mg3(PO4)2

Family: 
Phosphates
Space group: 
Monoclinic - Prismatic HM symbol (2/m) Space Group: P 21/a
Dana class: 
38.3.1.2VII - 38 Anhydrous Phosphates, etc ; 38.3 Anhydrous Phosphates, etc (A+ B++)3 (XO4)2 ; 38.3.1

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
262.858 95.250 (Ref.: 84nri) Nriagu J.O., 1984, Formation and stability of base metal phosphates in soils and sediments, Chap. 10. In: Phosphate Minerals, J.O. Nriagu and P.B. Moore (Eds), Springer-Verlag, ISBN 3-540-12757-7, 318-329 -3550129 (Ref.: 68rac/sop) Racz G.J., Soper R.J., 1968, Solubility of dimagnesium phosphate trihydrate and trimagnesium phosphate. Can. J. Soil Sci., 48, 265-269 -3792107 (Ref.: Internal calculation) 189.200 (Ref.: 74nau/ryz) Naumov G.B., Ryzhenko B.N., and Khodakovsky I.L., 1974. Handbook of Thermodynamic Data. U.S. Geol. Surv.WRD 74 001, 328 pp. 213.44 (Ref.: 63oet/mdo) Oetting F.L., Mac Donald R.A., 1963, The thermodynamic properties of magnesium orthophosphate and magnesium pyrophosphate. J. Phys. Chem., 63, 2737-2743
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.
261.54 76.36 -63.00 (Ref.: 63oet/mdo) Oetting F.L., Mac Donald R.A., 1963, The thermodynamic properties of magnesium orthophosphate and magnesium pyrophosphate. J. Phys. Chem., 63, 2737-2743
Reaction properties

Farringtonite + 4H+ ⇌ 3Mg+2 + 2H2PO4-

298.15 K, 1 bar log10K: 15.82 ΔH°r:-214093 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K 19.18 15.82 11.79 7.93 3.86 0.29 -3.07 -6.52
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-2186.454435 -0.351451 127677.229823 790.060795 -6767101.053854