220 likes | 420 Views
Stoichiometry w /Percent Yield and Limiting Reagent . Admit Slip. Write the action required for each arrow of the diagram. Agenda. Admit Slip Notes Classwork Product: Notes and Classwork Homework : Problems #1-3. Today’s Objectives. Students will be able to:
E N D
Stoichiometry w/Percent Yield and Limiting Reagent
Admit Slip • Write the action required for each arrow of the diagram.
Agenda • Admit Slip • Notes • Classwork Product: Notes and Classwork Homework : Problems #1-3
Today’s Objectives • Students will be able to: • Convert the mass or moles of one substance to the mass or moles of another substance in a balanced chemical reaction (stoichiometry) • Calculate percent yield • Calculate the limited reagent
Percent Yield and Limited Reagent 4/22/13 • Often in a chemical reaction, you do NOT make as much as you should make according to stoichiometry. • For every percent yield problem, you will calculate how much you SHOULD make of a product (the theoretical amount) • Also, you will be given an amount that is ACTUALLY made of that product. • You compare these two amounts through this equation. Percent = Actual Amountx 100% Yield Theoretical Amount
Percent Yield Example • 4 C3H5O + 15 O2 12 CO2 + 10 H2O • In the lab, you only produce 10 mol of CO2 from 18 mol of O2. What is the percent yield? • a) How many mol CO2 should you make? • b) What is the percent yield?
Limited Reagent/Reactant • A limited reactant question is the same idea as the following question: You have15 chocolate chips and 20 cups of sugar. Which one will cause you to make less cookies? • For a limited reagent question, you use the amounts of reactants given and figure out which reactant will give you less products. • It doesn’t matter which product you pick, you should get the same answer either way.
Limited Reactant Example C3H8 + 5 O2 3 CO2 + 4 H2O • Given 10 mol of C3H8and 30 mol of O2, which is the limited reactant? • Determine how much these amounts would make of one of the products, (ex. CO2). Whichever reactant makes less (CO2) is the limited reactant.
Classwork C5H12 +8 O2 5 CO2 + 6 H2O pentane oxygen carbon dioxide water 1. How many moles of pentane would be needed to form 8 moles of water ? 8 mol H2O *
C5H12 +8 O2 5 CO2 + 6 H2O pentane oxygen carbon dioxide water 2. Given 18 moles of O2, how many moles of CO2 will be formed?
C5H12 +8 O2 5 CO2 + 6 H2O pentane oxygen carbon dioxide water 3. Given 200 g of C5H12 , how many moles of CO2 will be formed?
C5H12 +8 O2 5 CO2 + 6 H2O pentane oxygen carbon dioxide water 4. Given 1.6 moles of C5H12, how many grams of H2O will be formed?
C5H12 +8 O2 5 CO2 + 6 H2O 5. How many grams of O2 is necessary to form 106 g of CO2 ?
C5H12 +8 O2 5 CO2 + 6 H2O 6. How many grams of water will be formed from 250 g of C5H12 ?
The percent yield is ___________________________________ x 100%
C5H12 +8 O2 5 CO2 + 6 H2O 9. If you produce 7 moles of H2O from 20 moles of O2 , what is the percent yield?
C5H12 +8 O2 5 CO2 + 6 H2O 10. If you produce 16 moles of CO2 from 4 moles of C5H12, what is the percent yield?
C5H12 +8 O2 5 CO2 + 6 H2O 10. If you produce 16 moles of CO2 from 4 moles of C5H12, what is the percent yield?
11. In your own words, what is the limiting reactant/reagent? It is the reactant that _____________________________ ______________________________________
C5H12 +8 O2 5 CO2 + 6 H2O 12. Given 4 mol of C5H12 and 27 mol of O2 , which is the limiting reagent?
C5H12 +8 O2 5 CO2 + 6 H2O 13. Given 210 g of C5H12 and 128 g of O2, which is the limiting reagent?
C5H12 +8 O2 5 CO2 + 6 H2O Exit Slip Solve and explain the following problem in words! How many grams of O2 would you need to form 165 g of C5H12 ?