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CH 12 Review for TEST!!!. Stoichiometry Limiting Reactants Percent Yield. Start with a Balanced Equation!. __NH 3 + __NO __N 2 + __H 2 O. Start with a Balanced Equation!. 4 NH 3 + 6 NO 5 N 2 + 6 H 2 O What does the coefficients mean?
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CH 12 Review for TEST!!! Stoichiometry Limiting Reactants Percent Yield
Start with a Balanced Equation! • __NH3 + __NO __N2 + __H2O
Start with a Balanced Equation! • 4 NH3 + 6 NO 5 N2 + 6 H2O • What does the coefficients mean? • 4___NH3 + 6____NO 5____N2+ 6__H2O • 4 molecules NH3 + 6 molecules NO 5 molecules N2 + 6 molecules H2O • 4 moles NH3 + 6 moles NO 5 moles N2 + 6 moles H2O • 4 volumes NH3 + 6 volumes NO 5 volumes N2 + 6 volumes H2O
Use like a recipe (moles to moles) • 4 NH3 + 6 NO 5 N2 + 6 H2O • If you have 15 moles of NH3, how many moles do you need of NO? 4 moles NH3 = 15 moles NH3 6 moles NO X moles NO X = 22.5 moles of NO
Use like a recipe (grams to grams) • 4 NH3 + 6 NO 5 N2 + 6 H2O • If you have 96 grams of NO, how many grams of NH3 do you need? • 68 g NH3 = Xg NH3 180 g NO 96 g NO X= 36.3 g NH3
Use like a recipe (liters to liters) • 4 NH3 + 6 NO 5 N2 + 6 H2O • How many liters of Nitrogen gas will you make if you start with 13 liters of nitrogen monoxide? 6 (22.4L) NO = 13 L NO 5 (22.4 L) N2 X L N2 X = 10.8 L N2
Find your limiting reactant (reagent) • 4 NH3 + 6 NO 5 N2 + 6 H2O • If you have 102 grams of NH3 and 360 grams of NO, what is your percent yield if you made 140 g of water? • 68 g NH3 = 102 g NH3 180 g NO X g NO X = 270 g NO but you have 360 grams. • You have tons of NO, in fact you have an EXCESS. • Your limiting reagent is NH3
Find how much product you expect (THEORETICAL YIELD) • 4 NH3 + 6 NO 5 N2 + 6 H2O • If you have 102 grams of NH3 and 360 grams of NO, what is your percent yield if you made 140 g of water? • Use your limiting reagent in your calculation…that is what is determining how much product you can make. • 68 g NH3 = 102 g NH3 108 g H2OX g H2O X = 162 g H2O. This is your THEORETICAL YIELD
Percent Yield • 4 NH3 + 6 NO 5 N2 + 6 H2O • If you have 102 grams of NH3 and 360 grams of NO, what is your percent yield if you made 140 g of water? • Actual amount x 100 = % yield theoretical yield • 140 g H2O X 100 = 86% 162 g H2O