Starter

1. Starter • Find your collected solid from lab last week and measure the mass.

2. Why percent yield? • Usually, not all the product possible is actually formed. • because of error in lab procedure • theoretical yield • maximum amount of product possible • is calculated using limiting reactant • actual yield • the measured amount formed in lab reaction • always less than or equal to theoretical yield

3. Example 1 • If the reaction actually produced 1.02 grams of water, what is the percent yield?

4. Example 2 • If 72.0 g of C2H2 reacts with an excess of Br2 and 729 g of the product is recovered, what is the percent yield? C2H2 + Br2 CHBr2CHBr2 • Do we need to find the LR first? • No- they tell you that the C2H2 is LR • How do we find the theoretical yield? • start with the LR and convert to product

5. Example 2 • Find the theoretical yield: • Calculate the percent yield:

6. Example 3 • If the percent yield of the reaction below is 73.8% and the reaction began with 24.3 g of CaO, how many grams of Ca(OH)2 were created? CaO + H2O  Ca(OH)2 • know percent yield • trying to find actual yield • need to calculate the theoretical yield first

7. Example 3 • Find the theoretical yield from LR first: • Solve for actual yield: