2. Moles and Particles How many moles are in 4.65 x 10 22 water molecules? Starting quantity? Particles Ending quantity? Moles Conversion factor: 1 mole = 6.02 x 10 23 water molecules Want to replace particles with moles

3. Moles and Particles 4.65 x 10 22 water molecules ÷ 6.02 x 10 23 water molecules per mole = 0.0772 moles water

4. Moles and Mass How many moles are in 25.8 g water? Starting quantity? Mass Ending quantity? Moles Conversion factor: 1 mole water = 18.0 g water (molecular weight of water) Want to replace mass with moles

5. Moles and Mass 25.8 g water ÷ 18.0 g water per mole water = 1.43 moles water

6. Moles and Volume How many moles are in 0.876 L of water vapor at STP? Starting quantity? Volume Ending quantity? Moles Conversion factor: 1 mole water vapor = 22.4 L water vapor at STP Want to replace volume with moles

7. Moles and Volume 0.876 L water vapor ÷ 22.4 L water vapor per mole water vapor = 0.0391 moles water

8. Thought Questions What do you notice about the conversion factors in the past three problems? What do you think you would do with these conversion factors if you started with moles? What do you think you would do if your starting and ending quantities were mass and volume? Mass and number of particles? Volume and number of particles?

9. Group Work Get into groups of 3-4 Grab one sheet of paper and some markers for each group Work on your assigned problem for 5 minutes – feel free to make it as colorful as possible to show each quantity (moles, mass, volume, number of particles) Present your solution to the class