Cu2S can be prepared by heating copper strongly in sulfur vapour or H2S. The reaction of copper powder in molten sulfur rapidly produces Cu2S, whereas pellets of copper require much higher temperature. Cu2S reacts with oxygen to form SO2: 2 Cu2S + 3 O2 → 2 Cu2O + 2 SO.

The copper wire reacts readily with the hot sulfur gas (S8, S4 and S2), forming a dark grey, brittle crystalline solid of copper sulfide.

While copper forms 2 different ions – Cu1+ and Cu2+, only one compound is formed – you will determine what the empirical formula of the compound you form is. Upon heating, the excess sulfur vaporizes to form gaseous sulfur, which escapes from the crucible.

When copper is heated with an excess of sulfur, copper(I) sulfide is formed. In a given experiment, 1.50 g of copper was heated with excess sulfur to yield 1.75 g copper(I) sulfide. What is the percent yield? According to the equation, 1 mole of Cu2S can be produced from 2 moles of Cu.

159.16 g/mol

Copper(I) sulfide

Copper(II) Sulfide Properties (Theoretical)

CuS is widely used as high capacity cathode material in lithium secondary batteries. CuS has good electronic conductivity (103 S−1 cm) and high energy capacity (560 mA h−1 g). These properties enable CuS to be used as a cathode material in lithium batteries.

79.853%

Although hydrochloric acid does not dissolve copper sulfides, an acid ferric chloride solution appears superior to ferric sulfate for oxidation and dissolution of chalcocite. Such a solution can be conveniently made by addition of sodium chloride to a sulfuric acid-ferric sulfate solution.

CuS

Percent composition by element

Chile