n CuO = 96/80 = 1,2 moli
m Cu = 1,2×64 = 76,8g
n = m/M = V/Vm =>m S = M×V/Vm = 32×53,76/22,4 = 76,8g
n S = 76,8/32 = 2,4 moli
m Fe = 220,8-(76,8+76,8) = 67,2g Fe
n Fe = 67,2/56 = 1,2 moli
Aflam formula bruta impartind rezultatul cel mai mic la toate rezultatele => CuFeS2