Copper reacts with sulfur to form copper (2) sulfide, there were 2.00 grams of copper, how many grams of cu2s can be formed?

Answer 1

Your question is a little confusing since in the beginning you refer to copper(2) sulfide, which could mean copper(II) sulfide which is CuS. In the next part, you refer to Cu2S, which is actually copper(I) sulfide. So, I'm not sure which you are producing. It's either copper(II) sulfide, CuS or it's copper(I) sulfide, Cu2S. I'll do it both ways.

In intro chem. you may refer to sulfur in a reaction as S, but in reality it exists as S₈, so I'll use the S₈ in this calculation.

The reaction for making CuS is:

8Cu + S₈ ==> 8CuS ... balanced equation

The reaction for making Cu₂S is:

16Cu + S₈ = 8Cu₂S ... balanced equation

Use dimensional analysis and the mole ratios in the balanced equation to find the grams of product.

atomic mass Cu = 63.6 g / mol

molar mass CuS = 95.6 g / mol

molar mass Cu₂S = 159 g / mol

For making CuS:

2.00 g Cu x 1 mol Cu / 63.6 g x 8 mol CuS / 8 mol Cu x 95.6 g CuS / mol = 3.01 g CuS

For making Cu₂S:

2.00 g Cu x 1 mol Cu / 63.6 g x 8 mol Cu₂S / 16 mol Cu x 159 g Cu₂S / mol = 2.50 g Cu₂S