2. Reaction Stoichiometry Weight relations in chemical reactions: 1.If I react this much, how much product do I get? 2.If I need this much product, how much do I need to react

3. 1. If you have 200 tires, how many cars can you make? 1. 2002. 1003. 8004. 50 2. If you have 200 tires, how many motorcycles can you make? 1. 2002. 1003. 8004. 50

5. 3. Consider: Pb(NO 3 ) 2 (aq) + 2 NaCl(aq) --> PbCl 2 (s) + 2 NaNO 3 (aq) If you have 5 moles of Pb(NO 3 ) 2, how many moles of PbCl 2 can you make? 1. 52. 103. 2.5 4. Consider: Pb(NO 3 ) 2 (aq) + 2 NaCl(aq) --> PbCl 2 (s) + 2 NaNO 3 (aq) If you have 5 moles of NaCl, how many moles of PbCl 2 can you make? 1. 52. 103. 2.5

6. How to Balance Equations One element at a time Trial and error Al + Br 2 Al 2 Br 6

7. CH 3 CH 2 OH + O 2 CO 2 + H 2 O CH 3 OH + O 2 CO 2 + H 2 O

8. General Stoichiometry Route Grams reactant Moles reactant Moles product Grams product 2 CH 3 OH + 3 O 2 2 CO 2 + 4 H 2 O If we react 100 grams of CH 3 OH, how many grams of H 2 O are formed? amounts table

11. 2 H 2 O 2 O 2 + 2 H 2 O If we react 12 grams of 30% H 2 O 2, how many grams of O 2 are formed?

14. Limiting Reactants 1. If you have 200 tires and 75 steering wheels, how many cars can you make? 1. 200 2. 75 3. 50 4. 100

15. Example 2. A cake recipe calls for 3 eggs, 2 cups of flour, and 3 teaspoons of sugar. If you have: 9 eggs 8 cups of flour 12 teaspoons of sugar how many cakes can you make? Enter the number of cakes.

16. Example 3. Which reaction is correct? 2 CO(g) + O 2 (g)  2 CO 2 (g)

19. A hard OWL Question:

20. Alum Lab Calculations: Let’s say you start with 0.985 g Al and make 14.8 g KAl(SO 4 ) 2  12 H 2 O product. What is the percent yield? Molar masses: Al = 26.98; KAl(SO 4 ) 2  12 H 2 O = 474.37 g/mol

21. Chemical Analysis

22. Chemical Analysis: Determining Formulas