Welcome: 3/10/14 Answer the following question: CaCO 3  CaO + CO 2 How many grams of CO 2 can be made from g of CaCO 3 ?

235.0 g CaCO g CaCO 3 1 mol CaCO 3 1 mol CO g CO 2 = g CO 2

Section 12.4 — Percent Yield Do you always get the amount of product calculated from stoichiometry?

What is percent yield? Theoretical Yield– The maximum amount of product that can be produced from a given amount of reactant (number found through stoichiometry) A chemical reaction rarely produces the theoretical yield of product Chemists must calculate the actual yield of a reaction through careful experiment where the mass of product is measured

What is percent yield? Actual Yield– The amount of product actually produced when the chemical reaction is carried out in an experiment Percent Yield– Ratio of actual yield to the theoretical yield % yield = actual yield/theoretical yield x 100

Percent Yield Example Example: From the following balanced equation CaCO 3  CaO + CO 2 My theoretical yield of carbon dioxide was 103 g. If 97.5 g of carbon dioxide was actually collected, what was my percent yield?

Percent Yield Example Example: From the following balanced equation CaCO 3  CaO + CO 2 My theoretical yield of carbon dioxide is 103 g. If 97.5 g of carbon dioxide is actually collected, what is my percent yield? Percent yield = Actual yield Theoretical yield x g CO g CO 2 x 100 Percent yield = 94.7%

Practice Problem #1

Percent Yield Example Example: From the following balanced equation SiO 2 + 6HF  H 2 SiF 6 + 2H 2 O My theoretical yield of of H 2 SiF 6 is 48 g. If my percent yield is 95.4%, what is my actual yield?

Percent Yield Example Percent yield = Actual yield Theoretical yield x 100 x 48 g H 2 SiF 6 x 100 Example: From the following balanced equation SiO 2 + 6HF  H 2 SiF 6 + 2H 2 O My theoretical yield of of H 2 SiF 6 is 48 g. If my percent yield is 95.4%, what is my actual yield? 95.4 =

Think - pair - share What is theoretical yield? How do you determine the theoretical yield if it is not given to you? What is actual yield? What is our formula for percent yield?

Complete Worksheet Finish worksheet If you get done early, you may begin your HW:  Page 373, Section Assessment Q’s 30, 31, 32