2. Chapter 9 - Sections 1& 2 Suggested Reading: Pages 299 - 305 Stoichiometry

3. The study of the quantitative, or measurable, relationships that exist in chemical formulas and chemical reactions.Stoichiometry

4. 2 H 2 + O 2  2 H 2 O Interpreting Balanced Chemical Equations Based on the mole ratio

5. Mole Ratio indicated by coefficients in a balanced equation Molar ratio of H 2 to H 2 O is 2:2 (Simplify 1:1) Molar ratio of O 2 to H 2 O is 1:2 2 H 2 + O 2  2 H 2 O

6. 2 moles of hydrogen react with 1 mole of oxygen to produce 2 moles of water. 2 H 2 + O 2  2 H 2 O In terms of moles

7. 4 grams of hydrogen react with 32 grams of oxygen to produce 36 grams of water. 2 H 2 + O 2  2 H 2 O In terms of mass

8. Law of Conservation of Matter & Mass 2 moles H 2 react with 1 mole of O 2 to form 2 moles of H 2 O. 2 H 2 + O 2  2 H 2 O H2H2H2H2 O2O2O2O2 H2OH2OH2OH2O 2 mol 1 mol 2 mol 2 g 1 mol 32 g 1 mol 18 g 1 mol 4 g 32 g 36 g + = VERIFIED!VERIFIED!

9. 2 hydrogen molecules react with 1 oxygen molecule to produce 2 water molecules. Notice that the number of molecules is NOT the same on each side of the arrow. 2 H 2 + O 2  2 H 2 O In terms of molecules

10. 4 atoms of hydrogen react with 2 atoms of oxygen to produce 2 water molecules, which are 4 atoms of hydrogen and 2 atoms of oxygen. 2 H 2 + O 2  2 H 2 O In terms of atoms

11. 44.8 L of hydrogen gas react with 22.4 L of oxygen gas to produce 44.8 L of water vapor. Notice that the number of liters of gas is NOT the same on each side of the arrow. 2 H 2 + O 2  2 H 2 O In terms of volumes @ STP

12. Lead will react with hydrochloric acid to produce lead (II) chloride and hydrogen. How many moles of hydrochloric acid are needed to completely react with 0.36 moles of lead? Practice Problem #1 Practice Problem #1 Oh, no … where do I start?

13. Lead will react with hydrochloric acid to produce lead chloride and hydrogen. Write an equation and balance it. Pb + HCl  PbCl 2 + H 2 Pb + HCl  PbCl 2 + H 2 2

14. How many moles of hydrochloric acid are needed to completely react with 0.36 moles of lead? Determine Mole Ratio Pb + HCl  PbCl 2 + H 2 Pb + HCl  PbCl 2 + H 2 2 hydrochloric acid lead Coefficient = 1 Coefficient = 2 “wanted” “given”

15. How many moles of hydrochloric acid are needed to completely react with 0.36 moles of lead? Set up mole ratio “wanted” to “given” Pb + HCl  PbCl 2 + H 2 Pb + HCl  PbCl 2 + H 2 2 0.36 moles Pb 2 HCl =.72 moles HCl 1 Pb

16. Umm … It would require 0.72 moles of hydrochloric acid. Is that right? That’s Correct!

17. Hem, hem – you have 9 more problems … ready, go.