Iron (II) sulfide reacts with oxygen to produce iron (III) oxide and sulfur dioxide.

Question

4 Upper F e Upper S Subscript 2 solid plus 11 Upper O Subscript 2 gas yields 2 Upper F e Subscript 2 Upper O Subscript 3 solid plus 8 Upper S Upper O Subscript 2 gas

Question
How many moles of Upper F e Upper S Subscript 2 are needed to produce 10 moles of Upper F e Subscript 2 Upper O Subscript 3?

Answer options with 4 options
A.
4

B.
5

C.
10

D.
20

Answer 1

To answer this question, we need to use the stoichiometry of the reaction. According to the balanced equation:

4 FeS2 + 11 O2 → 2 Fe2O3 + 8 SO2

From the equation, we can see that the molar ratio between FeS2 and Fe2O3 is 4:2, or simplified, 2:1.

So, for every 2 moles of Fe2O3 produced, we need 4 moles of FeS2.

If we want to produce 10 moles of Fe2O3, we would need (10 moles Fe2O3) × (4 moles FeS2 / 2 moles Fe2O3) = 20 moles FeS2.

Therefore, the correct answer is option D. 20 moles.