One of the reactions used in the smelting of copper ores to produce copper metal and sulfur dioxide gas involves reacting copper(I) oxide with copper(II) sulfide. When 250 kg of solid copper(I) oxide is heated with 129 kg of solid copper(II) sulfide, 285 kg of copper metal is recovered.
a) Cu2O(s) + Cu2S(s) → 4Cu(s) + SO2(g)
b) Cu2O(s) + 2Cu2S(s) → 6Cu(s) + SO2(g)
c) Cu2O(s) + 2Cu2S(s) → 6Cu(s) + 2SO2(g)
d) 2Cu2O(s) + Cu2S(s) → 6Cu(s) + SO2(g)
