Whitlockite(low)

Formula : Ca3(PO4)2

Family: 
Phosphates
Space group: 
Trigonal - Ditrigonal Pyramidal HM symbol (3m) Space Group: R 3c
Dana class: 
38.3.4.1VII - 38 Anhydrous Phosphates, etc ; 38.3 Anhydrous Phosphates, etc (A+ B++)3 (XO4)2 ; 38.3.4

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
310.177 97.620 (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. -3884817 (Ref.: Internal calculation) -4120820 (Ref.: 71par/wag) 236.000 (Ref.: 71par/wag) 227.82 (Ref.: 60kel) Kelley, K.K., 1960, Contributions to the Data in Theoretical Metallurgy XIII: High Temperature Heat Content, Heat Capacities and Entropy Data for the Elements and Inorganic Compounds. U.S. Bureau of Mines Bulletin 584, 232 p.
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.
227.82 0.00 0.00 (Ref.: 60kel) Kelley, K.K., 1960, Contributions to the Data in Theoretical Metallurgy XIII: High Temperature Heat Content, Heat Capacities and Entropy Data for the Elements and Inorganic Compounds. U.S. Bureau of Mines Bulletin 584, 232 p.
Reaction properties

Whitlockite(low) + 4H+ ⇌ 3Ca+2 + 2H2PO4-

298.15 K, 1 bar log10K: 8.39 ΔH°r:-113380 J·mol-1 (Ref.: 71par/wag)
T(°C) 0 25 60 100 150 200 250 300
log10K 10.13 8.39 6.20 3.98 1.47 -0.88 -3.25 -5.89
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-1987.740998 -0.325331 112503.412167 721.857013 -6257660.477984