AP Chemistry Name Limiting And Excess Reactants & More 1. When 194g of sulfur dioxide and 88g of oxygen gas react, sulfur trioxide is produced. a. Which reactant is limiting? b. What is the theoretical yield of sulfur trioxide? c. How many grams of the excess reactant will be left? 2. 480 mL of 0.200M copper (II) nitrate reacts with 24.5g of zinc to form 4.89 g copper and zinc nitrate. a. Which reactant is limiting? b. What is the percent yield of copper? c. How much of the excess reactant will be in excess? 3. A dry cleaning agent, (M=146.99 g/mol), that contains C, H, and Cl is a suspected cancer causing agent. When a .250 g sample was studied by combustion analysis, 0.451g of CO2 and 0.0617 g of H2O formed.