<span>You must balance your equation correctly.
Here is your answer:
294gFeS2 x 1molFeS2/119.99 x 11mols O2/4mols FeS2--> 6.738mol O2
176gO2 x 1mol O2/32gO2 x 4mols FeS2/11mol FeS2--> 2mols FeS2
Now choose the molecule with the lowest amount (Limiting Reagent)
2molsFeS2 x 2molsFe2O3/4molsFeS2 x 159.7g
159.7g Fe2O3 grams produced.</span>
The answer is the third one because density is mass divided by volume so 80 divided by 10 is 8
Just choice D.
If you find the number of atoms of each element, you will find that only choice D has the same amounts on each side of the equation.