Limiting Reactant The limiting reactant is the reactant you run out of first. The excess reactant is the one you have left over. The limiting reactant determines how much product you can make
Calculating Limiting Reactant Do two stoichiometry problems. The one that makes the least product is the limiting reagent. For example Copper reacts with sulfur to form copper ( I ) sulfide. If 10.6 g of copper reacts with 3.83 g S how much product will be formed?
If 10.6 g of copper reacts with 3.83 g S. How many grams of product will be formed? 2Cu + S → Cu 2 S 10.6 g Cu 63.55g Cu 1 mol Cu 2 mol Cu 1 mol Cu 2 S 1 mol Cu 2 S 159.16 g Cu 2 S = 13.3 g Cu 2 S 3.83 g S 32.06g S 1 mol S 1 S 1 Cu 2 S 1 mol Cu 2 S 159.16 g Cu 2 S = 19.0 g Cu 2 S = 13.3 g Cu 2 S Cu is Limiting Reagent
Your turn Mg + 2HCl → MgCl 2 + H 2 If 10.1 g of magnesium and 2.87 g of HCl gas are reacted a) what is the limiting reactant? b) how many grams of hydrogen gas will be produced?
Your Turn II 2Al + 3CuSO 4 → Al 2 (SO 4 ) 3 + 3Cu If 10.3 g of aluminum are reacted with 51.7 g of CuSO 4 a) what is the limiting reactant? b) how much copper will be produced?