1. Limiting Reactants and Percentage Yield 9.2

2. Reactants Excess Reactant – will not be completely ______ up in a ______ that goes to __________ Limiting Reactant – is ________ completely in a ________ that goes to ___________ Sandwich example

3. Limiting Reactant If there are 152.5 grams of CO and 24.50 g of H 2, how much CH 3 OH could be produced? Need a balanced equation CO + 2H 2  CH 3 OH Determine # of moles of product

4. Limiting Reactant With 752.4 grams of ZnCO 3 and 1921 grams of C 6 H 8 O 7, which is the limiting reactant? How much Zn 3 (C 6 H 5 O 7 ) 2 is produced? 3ZnCO 3 + 2C 6 H 8 O 7  Zn 3 (C 6 H 5 O 7 ) 2 + 3CO 3

5. Limiting Reactant Identify the limiting reactant and calculate the theoretical yield of phosphorous acid (H 3 PO 3 ) if 225 grams of PCl 3 is mixed with 123 grams of H 2 O. PCl 3 + 3H 2 O  H 3 PO 3 + 3HCl

6. Yield Actual Yield – _________ amount of ________ from a reaction. Doesn’t always _______ amounts that it __________. –Don’t go to _____________ –________ equilibrium –Not _____ situations

7. Percent Yield % Yield – ____ of _____ ____to the ____________ yield multiplied by ____ % yield = actual yield x 100 theoretical yield theoretical yield

8. Calculating % Yield Determine the limiting reactant, the theoretical yield (in grams), if 14.0 g of N 2 are mixed with 9.0g H 2. N 2 + H 2  NH 3

9. Calculating % Yield Make sure the equation is balanced. Find limiting reactant first Then identify actual yield Then calculate % yield % yield = Actual/Theoretical x 100

10. Theoretical Yield Determine the limiting reactant and the theoretical yield if 16.1 grams of bromine are mixed with 8.42 grams of chlorine. Br 2 + Cl 2  2BrCl

11. Stoichiometry Review 2N 2 H 4 + (CH 3 ) 2 N 2 H 2 + 3N 2 O 4  6N 2 + 2CO 2 + 8H 2 O The density of N 2 H 4 is 0.982 g/mL How many mL of N 2 H 4 is needed to produce 20 grams of N 2 ?

12. Stoichiometry Review 2N 2 H 4 + (CH 3 ) 2 N 2 H 2 + 3N 2 O 4  6N 2 + 2CO 2 + 8H 2 O How many molecules of N 2 H 4 are needed to produce 50 grams of N 2 ?