Chapter 9 Stoichiometry Review
1. What does a balanced equation allow you to determine?
2. What do the coefficients in a balanced equation represent?
3. How many mole ratios can be determined from the chemical equation:
2NO® N2 + O2?
4. In the reaction Ca + Cl2® CaCl2, what is the mole ratio of chlorine to calcium chloride?
5. What are the characteristics of a limiting reactant?
6. What are the characteristics of an excess reactant?
7. What is the equation for percent yield?
8. Define actual yield.
9. Define theoretical yield.
10. How do the actual and theoretical yields compare?
Percent Yield Practice Problems
Use the equation Ag2S + 2HCl à 2AgCl + H2s to answer questions 11 and 12
11. If the theoretical yield of AgCl from the equation was 48.7g, but the actual yield when the product was weighed after the reaction was 40.2g, what was the percent yield of AgCl?
12. At the completion of her lab, Ashley measured the mass of H2S at 7.1g. Her Stoichiometry calculations showed that her yield should have been 9.2g. What was the percent yield in her experiment?
Stoichiometry Problems
Remember correct significant figures and correct units!
Show your work!
Use the equation below to answer questions 13 – 21.
2Ca3(PO4)2 + 6SiO2 + 10C à 6CaSiO3 + 10CO + P4
13. Determine the number of moles of carbon required to produce 0.500 mol of P4.
14. Determine the number of moles of carbon required to consume 3.0 moles of SiO2.
15. Determine the number of moles of carbon required to consume 0.51 moles of Ca3(PO4)2.
16. Determine how many grams of carbon are required to consume 6.01 moles of SiO2.
17. Determine the number of moles of P4 produced when 6.2 grams of Ca3(PO4)2 are consumed.
18. Determine the number of moles of CO produced if 2.00 grams of SiO2 are consumed.
19. Determine the mass of SiO2 consumed if 1.8 grams of C is consumed.
20. Determine the mass of P4 produced if 1.8 grams of C is consumed.
21. Determine the mass of C consumed if 12.4 grams of P4 is produced.