1. Bell Ringer Please take out a piece of paper and answer the following question individually: When magnesium metal is burned, it forms MgO. How many moles of oxygen gas are needed to burn 10 moles of Mg? A 2 B 5 C 10 D 20 VA Chemistry SOL 2003 MgO2O2 MgO+22 10 mol Mg x 2 mol Mg 1 mol O 2 = 5 mol O 2

2. Homework Answers Fill in the Blanks: quantitative reactant coefficient conservation is coefficients Word Problems: 1.0.72 mol HCl 2.1.0 mol HNO 3 3.0.19 mol CO 2 4.0.19 mol Al 5.180 g I 2 6.730 g Cl 2 7.7200 g NaCl 8.150,000 g Zn 9. 3.3 g H 2 10. 1700 g H 2 O 11. 10 g H 2 12. 700 g CO 2 500 g O 2

3. Chemistry Key Words When a substance is: Reacted Oxidized Reduced Needed Electrolyzed IT IS A REACTANT! When a substance is: Formed Produced Liberated Created Prepared IT IS A PRODUCT!

4. Chemistry Intuition How many moles of oxygen are liberated by the electrolysis of 3 moles of water? O2O2 H2OH2O?+ electricity H2H2 22 NaOH How many grams of sodium hydroxide are formed from the reaction of sodium chloride and water? +H2OH2ONaClHCl+?HOH

5. Calculate the amount of iron liberated when copper (II) reacts with ferric oxide. How much zinc is necessary to create 15 grams of zinc oxide? Chemistry Intuition ZnZnO?O2O2 +22 FeCu+Fe 2 O 3 ?CuO+323

6. c.1.9 g Ca 2 mol Al 3 mol Ca = x 0.85 g Al x 1 mol Ca 40.08 g Ca1 mol Al 26.98 g Al x For Today’s Quiz: 2 Mass-Mass word problems, 10 points each Watch for Significant Figures! Label EVERYTHING! CaAlCl 3 CaCl 2 Al322 ++ 3 points 2 points3 points 2 points 3 For Today’s Quiz:

7. Stoichiometry in 3-D! There are three more types of stoichiometry problems we will deal with today for gases: –Mass-Volume –Volume-Mass –Volume-Volume We have already learned about these three types of conversions: –Mole-Mole –Mass-Mole –Mass-Mass

8. Mass-Volume Problems Step 1: Write a BALANCED EQUATION Step 2: Convert given substance from mass to moles Step 3: Determine the mole ratio from the coefficients in the equation and convert from moles of given to moles of required substance Step 4: Convert the required substance from moles to volume in liters

9. Example: 2 H 2 + O 2 2 H 2 O 48.0 g H 2 O x 2 mol H 2 O 1 mol O 2 = 18.02 g H 2 O 1 mol H 2 O xx 22.4 L O 2 1 mol O 2 Mass-Volume Problems How many liters of oxygen are necessary to create 48.0 g H 2 O? 29.8 L O 2

10. Volume-Mass Problems Step 1: Write a BALANCED EQUATION Step 2: Convert given substance from volume in liters to moles Step 3: Determine the mole ratio from the coefficients in the equation and convert from moles of given to moles of required substance Step 4: Convert the required substance from moles to mass in grams using the Periodic Table

11. Example: 2 H 2 + O 2 2 H 2 O 36.0 L O 2 x 1 mol O 2 2 mol H 2 O = 22.4L O 2 1 mol O 2 xx 18.02 g H 2 O 1 mol H 2 O Volume-Mass Problems How many grams of water are formed by reacting 36.0 L O 2 ? 58.7 g H 2 O

12. Volume-Volume Problems Step 1: Write a BALANCED EQUATION Step 2: Convert given substance from volume in liters to moles Step 3: Determine the mole ratio from the coefficients in the equation and convert from moles of given to moles of required substance Step 4: Convert the required substance from moles to volume in liters

13. Example: 2 H 2 + O 2 2 H 2 O 5.0 L O 2 x 1 mol O 2 2 mol H 2 = 22.4 L O 2 1 mol O 2 xx 22.4 L H 2 1 mol H 2 Volume-Volume Problems How many liters of H 2 are required to react with 5.0 L O 2 ? 10. L H 2

14. Practice Problems 2 H 2 O (g) 2 H 2 (g)O 2 (g)+ 1. a.63.07 g H 2 O 1 mol H 2 O 18.02 g H 2 O = x 78.40 L H 2 Mole ratio x 2 mol H 2 2 mol H 2 O1 mol H 2 x b.63.07 g H 2 O 1 mol O 2 2 mol H 2 O = x 39.20 L O 2 1 mol H 2 O 18.02 g H 2 O x 22.4 L O 2 1 mol O 2 x 22.4 L H 2

15. Practice Problems 2 H 2 O (g) 2 H 2 (g)O 2 (g)+ 39.2 L H 2 O 1 mol H 2 O 22.4 L H 2 O = x 39.2 g H 2 Mole ratio x 2 mol H 2 2 mol H 2 O1 mol H 2 x b.39.2 L H 2 O 1 mol O 2 2 mol H 2 O = x 19.6 g O 2 1 mol H 2 O 22.4 L H 2 O x 22.4 L O 2 1 mol O 2 x 22.4 L H 2 2. a.

16. 2 C 2 H 6 (g) 4 CO 2 (g)6 H 2 O (g)+ 3. a.16.0 g O 2 1 mol O 2 32.00 g O 2 = x 6.40 L CO 2 Mole ratio x 4 mol CO 2 7 mol O 2 1 mol CO 2 x b. 16.0 g O 2 6 mol H 2 O 7 mol O 2 = x 9.60 L H 2 O 1 mol O 2 32.00 g O 2 x 22.4 L H 2 O 1 mol H 2 O x 22.4 L CO 2 + 7 O 2 Practice Problems

17. 2 C 2 H 6 (g) 4 CO 2 (g)6 H 2 O (g)+ 4. a.5.8 L O 2 1 mol O 2 22.4 L O 2 = x 3.3 L CO 2 Mole ratio x 4 mol CO 2 7 mol O 2 1 mol CO 2 x b. 5.8 L O 2 6 mol H 2 O 7 mol O 2 = x 5.0 L H 2 O 1 mol O 2 22.4 L O 2 x 22.4 L H 2 O 1 mol H 2 O x 22.4 L CO 2 + 7 O 2

18. For Wednesday’s Quiz: 2 word problems, 10 points each mass-volume, volume-mass, volume-volume Be aware of: Significant figures LABELS! Pay attention to the labels given in the problem! LABEL EVERYTHING! Formulas and equation writing