Question

a sample of copper wire with a mass of 1.659 g is heated with excess powdered sulfur until the copper has combined with the sulfur, and all the extra sulfur has been burned off. The final product (a sulfide of copper ) has a mass of 2.080 g. Calculate the empirical formula of the product, and name it.

Answer 1

Copper mass = 1.659
Copper moles = 1.659 / 64 = 0.0259

Sulfur mass = 2.08 - 1.659 = 0.421
Sulfur moles = 0.421  / 32 = 0.0131

Ratio Copper : Sulfur = 2 : 1

Empirical formula: Cu ₂ S
Name: Copper (I) sulfide