Answer to Question #86439 in General Chemistry for Ainslea

Question

When 250 kg of copper (I) oxide is heated with 129 kg of copper (I) sulfide, 285 kg of copper is recovered. Calculate the theoretical yield of copper.

Answer 1

2Cu₂O + Cu₂S -> 6Cu + SO₂

n= m/M

n(Cu₂O)= 250000g/143.09g/mol= 1747 mol

n(Cu₂S)= 129000g/ 159.16 g/mol= 810.5 mol

Find limiting reactant: compare

1747/2 and 810.5

873.5>810.5, consequently , Cu₂S is a limiting reactant.

According to equation mole ratio n( Cu₂S):n(Cu)= 1:6, then n(Cu)= 6*n(Cu₂S)= 6*810.5 = 4863 mol.

m(Cu)= 63.55*4863=

309044 g= 309.044 kg.

% yield = (285 kg/309.044 kg )*100% = 92.2%

Answer: 92.2%