# Question b5376

Mar 15, 2016

$8.3997$x${10}^{25}$ atoms of $C u$

#### Explanation:

1. We need to balance the equation to determine the mole ratio of $C u$ against the $C {u}_{3} F e {S}_{3}$;
2. The balanced equation is:
$2 C {u}_{3} F e {S}_{3} + 7 {O}_{2} \to 6 C u = 2 F e O + 6 S {O}_{2}$
3. Find the formula mass of bornite, by locating the atomic masses of the elements composing the copper ore, which is equal to 344 grams per mole;
4. To start the calculation, you are provided with the mass of the raw material of $20 k g$ which has 80% purity. Meaning 80%# of the raw material is bornite (copper ore). To find the mass of copper ore, multiply the mass by its purity; so that
$20 k g$x$0.80 = 16 k g$ of pure bornite
5. Convert the mass (kg) of pure bornite to grams to be consistent with the units being used in the formula mass; ($16 , 000$ grams)
6. Again, $16 , 000$ grams bornite will be converted to mole bornite by multiplying with the mole ratio reflected on the balanced equation above to arrive $139.53$ mole $C u$;
7. Since $1 m o l C u = 6.02$x${10}^{23}$ atoms $C u$, multiply the answer in step 6 by the conversion factor taken from this equaivalent statement, which is $\frac{6.02 x {10}^{23} a t m s C u}{1 m o l C u}$;
8. The answer is computed as 8.3997 x ${10}^{25}$ atoms $C u$