Bornite ( 2Cu

_{3}FeS

_{3} )

2Cu

_{3}FeS

_{3} + 7O

_{2} 6Cu +2FeO + 6SO

_{2}If 2.50 metric tons of bornite is reacted with excess O

_{2} and the process has an 86.3% yield of copper , what mass of copper is produced?

MY SOLUTION:

I got 0.871 tons of O

_{2} using the stoichiometric relation of bornite and Oxygen.

Then I used the amount of Oxygen (i.e 0.817 tons O

_{2}) to evaluate the the mass of Cu... (by means of stoichiometric relation again) and I got 1.39 tons of Cu.

Question : HOw do I use the 86.3 % yield of copper in getting the right answer.