Romarchite

Formula : SnO

Family: 
Oxides
Space group: 
Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 4/nmm
Dana class: 
4.2.5.1 (4)Simple Oxides(4.2)with a cation charge of 2+ (A++ O) (4.2.5)Dana Group
High temperature: 
Weathering in fresh water.
Geological context: 
Mineral from the weathering of tin cooking utensils submerged since 1830 in the Winnipeg River at Boundary Falls, Manitoba, Canada.

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
134.709 21.550 (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. -251913 (Ref.: Internal calculation) -280710 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p. 57.170 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p. 47.78 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 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.
43.74 13.56 0.00 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p.
Reaction properties

Romarchite + 2H+ ⇌ Sn+2 + H2O

298.15 K, 1 bar log10K: 2.23 ΔH°r:-13896 J·mol-1 (Ref.: 89cox/wag) Cox J.D., Wagman D.D., and Medvedev V.A., 1989. CODATA Key Values for Thermodynamics. Hemisphere Publishing Corp., New York, 279 p.
T(°C) 0 25 60 100 150 200 250 300
log10K 2.44 2.23 1.97 1.71 1.45 1.21 0.97 0.70
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-311.060704 -0.047538 17825.140384 112.735856 -1002750.465378