2 Percent YieldThe percent yield is the percentage of a certain product actually produced in a chemical reaction.The theoretical yield is predicted by a stoichiometry problem.
3 A. Percent Yieldmeasured in labcalculated on paper
4 A. Percent YieldWhen 45.8 g of K2CO3 react with excess HCl, 46.3 g of KCl are formed. Calculate the theoretical and % yields of KCl.K2CO3 + 2HCl 2KCl + H2O + CO245.8 g? gactual: 46.3 g
5 A. Percent Yield K2CO3 + 2HCl 2KCl + H2O + CO2 45.8 g ? g actual: 46.3 gTheoretical Yield:45.8 gK2CO31 molK2CO3g2 molKCl1 molK2CO374.55g KCl1 molKCl= 49.4g KCl
6 A. Percent Yield K2CO3 + 2HCl 2KCl + H2O + CO2 45.8 g 49.4 g actual: 46.3 gTheoretical Yield = 49.4 g KCl46.3 g49.4 g% Yield = 100 =93.7%
7 Percent YieldThe reaction between SO2 and oxygen yields SO3.. Calculate the percent yield of SO3 if 40.0 grams of SO3is formed, when 32 grams of SO2 react with an excess of oxygen.SO2 + O2 SO32SO2 + O2 2SO3
8 B. Limiting Reactants Available Ingredients Limiting Reactant 4 slices of bread1 jar of peanut butter1/2 jar of jellyLimiting ReactantbreadExcess Reactantspeanut butter and jelly
9 B. Limiting Reactants Limiting Reactant Excess Reactant used up in a reactiondetermines the amount of productExcess Reactantadded to ensure that the other reactant is completely used upcheaper & easier to recycle
10 B. Limiting Reactants 1. Write a balanced equation. 2. For each reactant, calculate the amount of product formed.3. Smaller answer indicates:limiting reactantamount of product
11 Limiting Reactant Steps (version 2) Step oneWrite and balance the equation for the reaction.Step twoConvert known masses to grams of product.Step threeDetermine limiting reactant and amount that can be made.Step fourDetermine the grams of excess from limiting reactant.
12 B. Limiting Reactants Zn + 2HCl ZnCl2 + H2 79.1 g ? L 0.90 L 2.5M 79.1 g of zinc react with 0.90 L of 2.5M HCl. Identify the limiting and excess reactants. How many liters of hydrogen are formed at STP?Zn HCl ZnCl H279.1 g0.90 L2.5M? L
13 A. Limiting Reactants Zn + 2HCl ZnCl2 + H2 79.1 g 0.90 L 2.5M ? L g Zn1 molZn65.39g Zn1 molH2Zn22.4 LH21 mol= 27.1 LH2
14 A. Limiting Reactants Zn + 2HCl ZnCl2 + H2 79.1 g 0.90 L 2.5M ? L 2.5 molHCl1 L1 molH22 molHCl22.4L H21 molH2= 25 L H2
15 A. Limiting Reactants Limiting reactant: HCl Excess reactant: Zn Zn: 27.1 L H2HCl: 25 L H2Limiting reactant: HClExcess reactant: ZnProduct Formed: 25 L H2left over zinc
16 Limiting Reagent or Reactant 2 (problem #2) How many grams of ammonia will be produced when 20.0 grams of potassium hydroxide react with 15.0 grams of ammonium sulfate?Step 12KOH + (NH4)2SO4 K2SO4 +2NH3 +2H2O
17 (NH4)2SO4 is the limiting reagent because it will make the least amount of product. It is the reactant that will run out first.