1. Calculations with Moles

2. No. of Particles No. of Moles No. of Grams No. of Liters X formula mass X 22.4 L/mol X 6.02 X 10 23  by

3. 3 types of calculations Between moles and mass (grams) Between moles and volume (liters) Between moles and # of particles (#)

4. Moles to mass (and back) For mass-mole conversions, the formula mass must be calculated for each substance using its formula and the Periodic Table.

5. Mole/Mass Conversions What is the mass of 3 moles of sugar, C 6 H 12 O 6 ? Step 1: See what the mole-map says! Remember, mass = grams! Take moles X formula mass to get grams.

6. Conversions What is the mass of 3 moles of sugar, C 6 H 12 O 6 ? Step 2: Find the formula mass of C 6 H 12 O 6. 6 X C = 6 X 12.0 = 72.0 6 X C = 6 X 12.0 = 72.0 12 X H = 12 X 1.0 = 12.0 6 X O = 6 X 16.0 = 96.0 180.0

7. Conversions Step 3: 180.0 grams C 6 H 12 O 6 per mole X 3 moles 3 moles C 6 H 12 O 6 X 180.0 g = 540.0 g 1 mole

8. Mole-mass conversions How many moles of C 6 H 12 O 6 are in 270.0 grams of C 6 H 12 O 6 ? Step 1: Look at the mole map! Take grams and divide by formula mass to get moles. Step 2: Formula mass of C 6 H 12 O 6 = 180 g.

9. Mole-mass conversions How many moles of C 6 H 12 O 6 are in 270.0 grams of C 6 H 12 O 6 ? Step 3: 270.0 g  180 grams per mole = 1.5 moles

10. Mole-Volume Conversions For any gas, 1 mole = 22.4 liters at 1 atm pressure and 0  C. This is the only fact we need for mole/volume conversions. STP = standard temperature and pressure = 1 atm and 0  C

11. Mole-Volume Conversions What is the volume occupied by 4 moles of H 2 gas at STP? Step 1: Look at the mole map! Volume = # of moles X 22.4 L per mole

12. Mole-Volume Conversions What is the volume occupied by 4 moles of H 2 gas at STP? Step 2: Do the calculation! 4 moles X 22.4 L = 89.6 Liters 1 mole

13. Mole-Volume Conversions How many moles of N 2 are in 33.6 liters? Mole map says: take the liters and divide by 22.4 liters per mole.

14. Mole-Volume Conversions How many moles of N 2 are in 33.6 liters? Step 2: Do the calculation: 33.6 Liters  22.4 L per mole = 1.5 moles