Hi,

I am working on stoichiometry and limiting reactant problems. I have worked through examples in my book and I did them right and can solve for the excess, however there is one problem in the book that has confused me. I don't understand why they identified the limiting reactant as the one they did.

Equation
S8+4Cl2------4S2Cl2

200g of sulfur reacts with 100g of chlorine, what mass of disulfur dichloride is produced?

100g Cl2 *1mol cl2/70.91gcl2=1.410 mol Cl2

200g S2*1mol S8/256.5gS8=0.7797 mol S8

Isn't Sulfur the limiting reactant??? My book says its chlorine but I don't see how that is possible since sulfur is smaller and the ratio shows that.

1 answer

Since 1 mole of S8 reacts with 4 moles of Cl2,

.779 moles S8 will need 3.116 moles of Cl2, but you only have 1.410 moles

Clearly the Cl2 is lacking here.