Answer:
150 g of chalcocite (Cu) contain the same mass of Cu than 250 pounds of chalcopyrite.
Explanation:
First, we need to pass 250 pound to the metric system using the relationship 1 lbs = 453g. Then,
[tex]250lbs(CuFeS_{2}).\frac{453g(CuFeS_{2})}{1lbs(CuFeS_{2})} =1.13 \times 10^{5} g(CuFeS_{2})[/tex]
Secondly, we look for the mass of copper in 1.13 x 10⁵ grams of CuFeS₂, knowing that there are 63.5g of Cu in 183.5 g of CuFeS₂ (molar masses).
[tex]1.13\times 10^{5} g(CuFeS_{2})\frac{63.5gCu}{183.5g(CuFeS_{2})} =99.5gCu[/tex]
Finally, we find the mass of CuS that contains 99.5 g of Cu, knowing that 63.5 g of Cu are found in 95.5 g of CuS (molar masses).
[tex]99.5gCu.\frac{95.5gCuS}{63.5gCu} =150gCuS[/tex]