Hvermiculite(Mg)

Formula : Mg0.43Mg3.00Si3.14Al0.86O10(OH)2:4.55H2O

Space group: 
Monoclinic - Prismatic HM symbol (2/m) Space Group: C 2/m
Dana class: 
71.3.1b.2VIII- 71 Phyllosilicate Minerals ; 71.3 Phyllosilicates Phyllosilicate Sheets of Six-Membered Rings with 2:1 clays ; 71.3.1b Smectite group (Trioctahedral Smectites)
High temperature: 
Low temperature mineral. At higher temperatures(> 500C), detachment of (OH) ions takes place.
Geological context: 
see vermiculite

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
470.737 221.913 (Ref.: 15bla/vie, 11vie/bla) -6833901 (Ref.: Internal calculation) -7432531 (Ref.: 15bla/vie, 11vie/bla) 610.554 (Ref.: 15bla/vie, 11vie/bla) 675.30 (Ref.: 15bla/vie, 11vie/bla)
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.
675.30 0.00 0.00 (Ref.: 15bla/vie, 11vie/bla)
Reaction properties

Hvermiculite(Mg) + 9.44H+ ⇌ 0.86Al+3 + 3.43Mg+2 + 3.14H4SiO4 + 3.99H2O

298.15 K, 1 bar log10K: 35.86 ΔH°r:-353588 J·mol-1 (Ref.: 15bla/vie, 11vie/bla)
T(°C) 0 25 60 100 150 200 250 300
log10K 41.41 35.86 29.30 23.30 17.42 12.75 8.80 5.21
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-2726.677578 -0.372151 175199.185698 967.569543 -9628510.312156