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Percent Yield. Theoretical Yield. The maximum amount of product that can be produced from a given amount of reactant Theoretical yield is calculated using stoichiometry. Actual Yield. The amount of product actually produced when the chemical reaction is carried out in an experiment.
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Theoretical Yield The maximum amount of product that can be produced from a given amount of reactant Theoretical yield is calculated using stoichiometry
Actual Yield The amount of product actually produced when the chemical reaction is carried out in an experiment
Percent Yield A comparison of the actual and theoretical yield In general, the higher the yield, the better the results are from the experiment. % Yield = actual yield (experiment) theoretical yield (calculation) × 100
Steps • Identify what is given in the problem. • One product and one reactant (go to step 2) • One product and two reactants (go to step 3) • The product given is the actual yield, calculate the theoretical yield using stoichiometry and the reactant given • The product given is the actual yield, calculate the limiting reactant and that becomes your theoretical yield • Calculate the percent yield using the equation
Determine the theoretical yield of Ag2CrO4 if 0.500 g of AgNO3 is used to react with K2CrO4. Also if 0.455 g of Ag2CrO4 is obtained from an experiment, calculate the percent yield. 2 AgNO3+ 1 K2CrO4 1 Ag2CrO4 + 2 KNO3 0.500g AgNO3 1 mol AgNO3 1 mol AgCrO4 331.74 g AgCrO4 169.88 g AgNO3 2 mol AgNO3 1 molAgCrO4 = 0.488 g AgCrO4 % Yield = Actual 0.455 g AgCrO4 Theoretical 0.488 g AgCrO4 ×100 = ×100 = 93.2%
CCl4 was prepared by reacting 100.0 g of CS2 and 100.0 g Cl2. Calculate the theoretical yield and percent yield if 65.0 g of CCl4 was obtained from the reaction. 1 CS2 + 3 Cl2 1 CCl4 + 1 S2Cl2 100.0g Cl2 1 mol Cl2 1 mol CCl4 153.8 g Ccl4 70.90 g Cl2 3 molCl2 1 mol CCl4 100.0g CS2 1 mol CS2 1 mol CCl4 153.8 g CCl4 76.15 g CS2 1 molCS2 1 mol CCl4 = 72.31 g CCl4 = 202.0 g CCl4 L.R. = theoretical % Yield = Actual 65.0 g CCl4 Theoretical 72.31 g CCl4 ×100 = ×100 = 89.9%
Silver bromide (AgBr) was prepared by reacting 200.0 g of magnesium bromide and 100.0 g of silver nitrate. Calculate the theoretical and percent yield if 100.0 g of silver bromide was obtained from the reaction. 1 MgBr2 + 2 AgNO31 Mg(NO3)2 + 2 AgBr 100.0g AgNO3 1 molAgNO3 2 molAgBr 187.77 g AgBr 169.88 g AgNO3 2 molAgNO3 1 molAgBr 200.0g MgBr2 1 mol MgBr2 2 molAgBr 187.77 g AgBr 184.11 g MgBr2 1 molMgBr2 1 molAgBr = 110.5 g AgBr =408.0g AgBr L.R. = theoretical % Yield = Actual 100.0 g AgBr Theoretical 110.5 g AgBr ×100 = ×100 = 90.5%