1. How many M&M’s do you have? Mass of weighing dish: Mass (bag & candy): Mass of bag alone: 1.555g Mass of candy: # of candies: Mass per candy: 0.850g Prediction:Actual:

2. MOLES A mole is –A chemist’s dozen –22.4 L of a gas at standard temperature and pressure –Avogadro’s number –The # of atoms/molecules needed to make the mass of a sample in grams equal to its mass in amu

3. Molar Mass 1 mole of a particular substance is equal to its formula mass You find this by adding up the atomic masses from the periodic table Example: NaCl –Sodium: 22.9877 g –Chlorine: 35.453 g1mole = 58.440 g of NaCl

4. Moles to Mass Examples How many grams are in 1mole of (C 10 H 6 O 3 )? How many moles are in 423 g of aluminum?

5. Moles to Molecules 6.02 × 10 23 molecules = 1 mole 6.02 × 10 23 molecules is known as Avogadro’s number

6. Moles to Molecules Examples How many molecules are there in 24 moles of zinc? How many moles are there in 2.06 ×10 22 molecules of magnesium?

7. Molecules to Mass Examples How many H 2 O molecules in 72 grams of H 2 O? How many grams of sugar (C 12 H 22 O 11 ) are there in 4.80×10 21 molecules?

8. Moles to Liters 1 mole = 22.4 Liters –This is always true at Standard Temperature (0°C / 273 Kelvin) and Standard Pressure (1 atm) →

9. Moles to Liters Examples There are 2.4 moles of Cl 2 gas collected in a gas chamber. How many liters is this? You have 233 Liters of H 2 O. How many moles do you have?

10. Liters to Molecules Example How many molecules are there in 56.8 Liters of carbon monoxide? How many Liters are there in 2.08×10 23 molecules of sodium chloride?

11. Liters to Mass Examples How many grams is 2.5 Liters of Oxygen gas? How many liters is 27 grams of Neon gas?