Hydroxyapatite(Natur)

Formula : Ca5(PO4)3(OH)

Family: 
Phosphates
Space group: 
Monoclinic - Domatic HM symbol (m) Space Group: P 63/m 6/
Dana class: 
41.8.1.0VII - 41 Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen ; 41.8 Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen where(?)5 (XO4)3 Zq ; 41.8.1
High temperature: 
It is stable in a wide range of temperature. Its stability at room temperature is possible.
Geological context: 
Apatite is the most abundant naturally occuring phosphate on Earth. Occurs in metamorphic rocks, sedimentary environments or precipitate from hydrothermal solutions

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
502.311 159.600 (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. -6330803 (Ref.: 06bla/pia) Blanc P., Piantone P., Lassin A. et Burnol A., 2006. Thermochimie : Selection de constantes thermodynamiques pour les elements majeurs, le plomb et le cadmium. Rapport final. Rapport BRGM 54902-FR -6730234 (Ref.: Internal calculation) 390.350 (Ref.: 71par/wag) 385.11 (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.
478.07 82.89 -104.60 (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

Hydroxyapatite(Natur) + 7H+ ⇌ 5Ca+2 + 3H2PO4- + H2O

298.15 K, 1 bar log10K: 14.34 ΔH°r:-178396 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K 17.08 14.34 10.90 7.42 3.49 -0.22 -3.98 -8.18
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-3090.158648 -0.512474 173282.298604 1124.736305 -9510669.684008