1. Chem Catalyst 1) How many eggs are in 2.5 dozen? 2) If apples are 3/$1, how much will 9 apples cost? 3) If a box of pasta is 16 oz., how much will 3 boxes of pasta weigh?

2. Today’s Agenda: 1. Catalyst 2. Introduce Unit 6: Stoichiometry 3. Introduce Chapter 10: Chemical Quantities 4. Notes- The mole! 5. HW: p. 296 #10, 13, 14

3. Unit 6: Stoichiometry Chapter 10: Chemical Quantities Chapter 12: Stoichiometry

4. Unit 6: Stoichiometry BIG Questions 1. Why do chemists use moles? 2. How does a chemical equation represent chemical quantities? 3. How can chemical quantities be manipulated?

5. Chapter 10: Chemical Quantities 10.1: The Mole: A Measurement of Matter - Avogadro’s number 10.2: Mole-Mass and Mole-Volume Relationships - Convert between moles and mass 10.3: Percent Composition and Chemical Formulas - Understanding the relationship between chemical formulas and quantities

6. The Mole - Set measurement of particles: SI Unit for measuring amount of substance - 1 mol = 6.02 x 10 23 particles - *** Known as Avogadro’s number - Particles can be atoms or molecules

7. Conversion: Particles to Moles - Multiply by (1 mol/ 6.02 x 10 23 particles) - Ex: How many moles is 2.80 x 10 24 atoms of silicon?

8. Conversion: Moles to Particles - Multiply by (6.02 x 10 23 particles/ 1 mol) - Ex: How many molecules are in 1.14 mol of SO 3 ?

9. Practice: 1) How many moles is 2.17 x 10 23 particles of Br 2 ? 2) How many moles is 1.25 x 10 23 atoms of Mg? 3) How many molecules are in 2.12 mol of propane? 4) How many molecules are in 3.5 mol of sodium hydroxide?