4FeS2 + 11 O2­ → 2 Fe2O3 + 8 SO2 Given 75.0 grams of FeS2, how many grams of sulfur dioxide are produced (MM in g/mol: FeS2=119.99, O2=32, Fe2O3=159.7, SO2=64.07) ? 40.0. g 70.0 g 150. g 80.0 g

1 Answer
Jan 20, 2018

=80.09g

Explanation:

  1. Write the balanced equation as presented.

    4FeS_2+11O_2->2Fe_2O_3+8SO_2

  2. Given the mass of FeS_2, per convention will be converted to mol. To do that, find the molar mass of the compound which is obtainable from the periodic table where the equivalence statement 1molFeS_2-=119.98gFeS_2 is derived.

    etaFeS_2=75.0cancel(g)xx(1mol)/(119.99cancel(g))
    etaFeS_2=0.625mol

  3. Now, referring to the balanced equation, take the mole ratio of the FeS_2 against the SO_2 which is found to be 4:8. This value provides the relationship that converts etaFeS_2 to etaSO_2; thus,

    etaSO_2=0.625cancel(molFeS_2)xx(8molSO_2)/(4cancel(molFeS_2))
    etaSO_2=1.250mol

  4. Finally, the problem is asking for the mass of SO_2 produced in the reaction. This case, molar mass is needed to again convert the value from mole to mass as shown below.

    mSO_2=1.250cancel(molSO_2)xx(64.07gSO_2)/(1cancel(molSO_2))
    mSO_2=80.09g