Jennite

Formula : Ca9Si6H22O32

Space group: 
Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Dana class: 
56.2.4.11 (56) Sorosilicate Si2O7 Groups and O, OH, F. and H2O (56.2) with cations in [4] and/or >[4] coordination (56.2.4) Cuspidine - Wohlerite group
High temperature: 
Stability of Jennite at low temperature cannot be dismissed.
Geological context: 
Jennite is a natural analog of the calcium silicate hydrate (CSH) phase that forms a major part of Portland cement.

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
1063.370 456.400 (Ref.: 92tay) Taylor, H. F. W., 1992, Cement Chemistry, third edition: London, Thomas Telford, 475 p. -13886954 (Ref.: 10abla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Temperature dependence of thermodynamic functions for nanocrystalline and crystalline C-S-H phases. Cement and Concrete Research, 40, p. 851-867 -15189040 (Ref.: 10abla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Temperature dependence of thermodynamic functions for nanocrystalline and crystalline C-S-H phases. Cement and Concrete Research, 40, p. 851-867 839.864 (Ref.: Internal calculation) 933.21 (Ref.: 10abla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Temperature dependence of thermodynamic functions for nanocrystalline and crystalline C-S-H phases. Cement and Concrete Research, 40, p. 851-867
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.
933.21 0.00 0.00 (Ref.: 10abla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Temperature dependence of thermodynamic functions for nanocrystalline and crystalline C-S-H phases. Cement and Concrete Research, 40, p. 851-867
Reaction properties

Jennite + 18H+ ⇌ 9Ca+2 + 6H4SiO4 + 8H2O

298.15 K, 1 bar log10K: 147.34 ΔH°r:-737766 J·mol-1 (Ref.: 10abla/bou) Blanc, Ph.; Bourbon, X.; Lassin, A.; Gaucher, E.C. 2010 - Chemical model for cement-based materials: Temperature dependence of thermodynamic functions for nanocrystalline and crystalline C-S-H phases. Cement and Concrete Research, 40, p. 851-867
T(°C) 0 25 60 100 150 200 250 300
log10K 159.05 147.34 133.78 121.62 109.98 101.00 93.67 87.20
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-4841.978295 -0.648813 319383.869781 1738.516623 -16916851.231368