Nomenclature
CAS number: 22205-45-4
Cu
2S; mol wt 159.16.
Cu 79.85%, S 20.15%.
Description and references
Occurs in nature as the mineral chalcocite also called copper glance (grey, black, green, blue, or violet rhombic crystals).
Prepn: Glemser, Sauer in Handbook of Preparative
Inorganic Chemistry vol. 2, G. Brauer, Ed.
(Academic Press, New York, 2nd ed., 1965) p 1016.
Properties
Blue to grayish-black lustrous powder, granules,
or orthorhombic crystals. mp ≈1100°. d420 5.6. On heating in the absence of air it
forms Cu and CuS; in the presence of air it forms CuO, CuSO4 and SO2. Practically insol in water, acetic acid; very
sparingly sol in HCl; dec by HNO3, concd H2SO4. Partially sol in NH4OH, readily in cyanide solns
due to complex ion formation.Use
In luminous paints; in electrodes for thermoelements;
in preparation of CuSO
4; in solid-lubricant compositions;
as catalyst.