Chalcocite(alpha)

Formula : Cu2S

Space group: 
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Dana class: 
2.4.7.1 (2) Sulfides - Including Selenides and Tellurides (2.4) where Am Bn Xp, with (m+n):p=2:1(2.4.7) Chalcocite Group ([Cu]2-x S] formulae)
High temperature: 
Chalcocite is stable under a normal atmospheric conditions.
Geological context: 
Secondary mineral in or near the oxidized zone of copper sulfide deposits.

Dernière mise à jour le 11.06.2018

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
cm3·mol-1
ΔGºf
J·mol-1
ΔHºf
J·mol-1
J·mol-1·k-1
CP
J·mol-1·K-1
159.158 27.480 -86223 -79496 120.918 76.32
Reaction properties

Chalcocite(alpha) + H+ ⇌ 2Cu+ + HS-

298.15 K, 1 bar log10K: -34.75 ΔH°r: -953897 J·mol-1
T(°C) 0 25 60 100 150 200 250 300
log10K -38.38 -34.75 -30.67 -27.01 -23.50 -20.86 -18.88 -17.51