1. Stoichiometry Mathematics & Science Center

2. Brainstorm What do you already know about chemical reactions?

3. Mole A Counting Number Equal To 6.02 X 10 23 individual units. A mass in grams equal to the atomic mass or the formula mass of a substance.

4. Write a Balanced Equation. State the Problem Above the Reactants and Products in the Equation Create a basic equation table from the balanced equation. 1 Add another row of cells. Restate the moles of the given and unknown quantities in the appropriate units. 2 Add an additional row of cells. State the given and unknown quantities. 3 Set the ratio of the last two cells in the given column equal to the ratio of the last two cells in the column containing ‘x’. All quantities except ‘x’ should have a label. 4 Solve for ‘x’ and express the final answer with the correct label. 5 C 3 H 8 + 5O 2 → 4 H 2 O + 3 CO 2 50 moles? mL

5. Exercise 1: Spacecraft Air 2LiOH + CO 2 Li 2 CO 3 + H 2 O

6. ? grams1400. g 2 moles1 mole 44.0 g47.8 g 1400. gX 44.0 g CO 2 1400. g CO 2 = 47.8 g LiOH X 2LiOH+ CO 2 Li 2 CO 3 + H2OH2OH2OH2O

7. 44.0 g CO 2 1400. g CO 2 = 47.8 g LiOH X X= (47.8g LiOH) (1400. g CO 2 ) _______________________________________________ 44.0 g CO 2 X= 1520g LiOH

8. Exercise 2: Combination Reaction 2 H 2 + O 2 2H 2 O

9. ? molecules550. g 1 mole 6.02 x 10 23 x 550. g 36.0 g 2 moles molecules 6.02 x 10 23 molecules O 2 x = 36.0 g H 2 O 550. g H 2 O 9.20 x 10 24 molecules O 2 X =

10. Exercise 3: Flamethrower C 3 H 8 + 5O 2 3CO 2 + 4H 2 O 12.9 g?g 46.9 g O 2 ? molecules 5.29 x 10 23 molecules ? mL 21.1 mL H 2 O

11. Limiting Reactant? Exercise 4: Combustion Reaction C + O 2 -----> CO 2 A charcoal briquette weighing 45 g is placed in a jar containing 115. g of oxygen. The briquette is lit and a lid is placed on the jar. How many grams of CO 2 can be produced by this combustion reaction?

12. C + O 2 ----> CO 2 C + O 2 ----> CO 2 1mole 12.0 g44.0 g 45.0 gX X = 165 g CO 2 32.0 g 115 g X = 158 g CO 2 Oxygen is the limiting reagent! 45g115 g ?g

13. Online Practice Electronic Flashcard http://garnet.acns.fsu.edu/~rlight/stoich/

14. What is stoichiometry?