Question

Two minerals that contain copper are chalcopyrite, CuFeS2, and chalcocite, Cus. What mass of chalcocite would contain the same mass of copper as is contained in 250 pounds of chalcopyrite?

Answer 1

150 g of chalcocite (Cu) contain the same mass of Cu than 250 pounds of chalcopyrite.

Step-by-step explanation:

First, we need to pass 250 pound to the metric system using the relationship 1 lbs = 453g. Then,

`250lbs(CuFeS_(2)).(453g(CuFeS_(2)))/(1lbs(CuFeS_(2))) =1.13 * 10^(5) g(CuFeS_(2))`

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).

`1.13* 10^(5) g(CuFeS_(2))(63.5gCu)/(183.5g(CuFeS_(2))) =99.5gCu`

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).

`99.5gCu.(95.5gCuS)/(63.5gCu) =150gCuS`