Question

How much chalcopyrite had to be mined to produce 100 pennies if reaction 1 had a percent yield of 68.00 % and all other reaction steps had yield of 100%?

Answer 1

Well if you do the math , it come up to about 20

Answer 2

`m_(CuFeS_2)=1273.8gCuFeS_2`

Step-by-step explanation:

Hello,

In this case, the set of chemical reactions are shown below:

(1) 2 CuFeS₂ + 3 O₂ ----> 2 CuS + 2 FeO + 2 SO₂

(2) 2 FeO + SiO₂ ----> 2 FeSiO₃

(3) 2 CuS ----> Cu₂S + S

(4) Cu₂S + S + O₂ ----> 2 Cu + 2 SO₂

In such a way, the pennies are assumed to be 100% copper, and each penny has about 3.0 g of copper, so based on the 4th reaction, we compute moles of Cu₂S and pass through until the 1st reaction as shown below:

`n_(Cu_2S)=100pennies*(3.0gCu)/(1penny)*(1molCu)/(63.5gCu)*(1molCu)/(2molCu) \\n_(Cu_2S)=2.36molCu_2S`

Now, from the 3rd reaction we compute the moles of CuS:

`n_(CuS)=2.36molCu_2S*(2molCuS)/(1molCu_2S)=4.72molCuS`

2nd reaction is needless, so we proceed to compute CuS's theoretical amount since the 4.72 mol of CuS are said to be actually obtained (real amount) as shown below:

`n_(CuS)^(theoretical)=(n_(CuS)^(real))/(Y)=(4.72molCuS)/(0.68) \\n_(CuS)^(theoretical)=6.94molCuS`

Now, we develop the shown-below stoichiometric relationship between CuS and the chalcopyrite to compute the required amount to be mined in grams, for example

`m_(CuFeS_2)=6.94molCuS*(2molCuFeS_2)/(2molCuS)*(183.54gmolCuFeS_2)/(1molCuFeS_2) \\m_(CuFeS_2)=1273.8gCuFeS_2`

Best regards.