Imogolite

Formula : Al2SiO3(OH)4

Space group: 
Monoclinic Space Group: ?
Dana class: 
71.1.4.3VIII- 71 Phyllosilicate Minerals ; 71.1 Phyllosilicates Phyllosilicate Sheets of Six-Membered Rings with 1:1 layers ; 71.1.4 Allophane group

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
198.076 73.400 (Ref.: 90rob/cam) Roberts, Willard L., Campbell, Thomas J., and Rapp, George R.: Encyclopedia of Minerals. (Van Nostrand Reinhold Co., 2nd ed., 1990) -2921297 (Ref.: 96su/har) Su, C., and J.B. Harsh. 1996. Influence of soluble aluminosilicate complex formation on imogolite solubility determination. Geochim. Cosmochim. Acta 60:4275-4277. -3189600 (Ref.: 82far/fra) V.C. Farmer and A.R. Fraser, Chemical and colloidal stability of sols in the Al2O3-Fe2O3-SiO2-H2O system: Their role in podzolization, J. Soil Sci. 33 (1982), pp. 737-742 154.909 (Ref.: Internal calculation)
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.
Reaction properties

Imogolite + 6H+ ⇌ 2Al+3 + H4SiO4 + 3H2O

298.15 K, 1 bar log10K: 13.08 ΔH°r:-203551 J·mol-1 (Ref.: 82far/fra) V.C. Farmer and A.R. Fraser, Chemical and colloidal stability of sols in the Al2O3-Fe2O3-SiO2-H2O system: Their role in podzolization, J. Soil Sci. 33 (1982), pp. 737-742
T(°C) 0 25 60 100 150 200 250 300
log10K 16.34 13.08 9.37 6.06 2.90 0.43 -1.66 -3.57
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-1434.402301 -0.201607 88284.886689 509.661750 -4412600.061655