Strengite

Formula : FePO4:2H2O

Family: 
Phosphates
Space group: 
Orthorhombic - Dipyramidal HM symbol (2/m 2/m 2/m) Space Group: Pcab
Dana class: 
40.4.1.2VII - 40 Hydrated Phosphates, etc ; 40.4 Hydrated Phosphates, etc where A+++ XO4 . x(H2O) ; 40.4.1

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
186.849 64.500 (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. -1657700 (Ref.: 69wag/eva) Wagman D.D., Evans W.H., Parker V.B., Halow I., Bailey S.M., Schumm R.H., 1969. Selected values of chemical thermodynamic properties. Natl. Bur. Stand. Tech. Note, 270-4, 152 p. -1888461 (Ref.: Internal calculation) 171.250 (Ref.: 69wag/eva) Wagman D.D., Evans W.H., Parker V.B., Halow I., Bailey S.M., Schumm R.H., 1969. Selected values of chemical thermodynamic properties. Natl. Bur. Stand. Tech. Note, 270-4, 152 p. 180.54 (Ref.: 74nau/ryz,76wag/eva, 71par/wag)
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.
180.54 0.00 0.00 (Ref.: 74nau/ryz,76wag/eva, 71par/wag)
Reaction properties

Strengite + 2H+ ⇌ Fe+3 + H2PO4- + 2H2O

298.15 K, 1 bar log10K: -5.25 ΔH°r:-34799 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K -4.72 -5.25 -5.93 -6.62 -7.41 -8.19 -9.05 -10.07
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-1075.604436 -0.171873 58848.891942 388.411982 -3278681.140530