Limiting reactant tutorial How many grams of solid aluminum sulfide are prepared by reaction of 10.0g of aluminum and 15.0g of sulfur? (1) Write the balanced reaction (write any coefficients of "1" explicitly): Al(s)+S(s)A2S3(s) (2) Determine the moles of each reactant: molAl(s)molS(s) (3) Determine limiting reactant: There are several ways to do this: (i) brute force (calculate the amount of products formed considering both possibilities alternately; (ii) compare the experimental mole ratios of the reactants with the required mole ratios from the balanced equation; (iii) divide the experimental moles by the coefficients in the balanced equation. The important thing to realize is that the limiting reactant is not necessarily the one with the fewest moles (a common mistake). is the limiting reactant. (4) Calculate amount of product, based on limiting reactant: mass of Al2S3(s)= grams