3. Mole Map Grams mole Volume of a Gas @ STP molecules atoms Atoms (element) 22.4 L 6.02 x 10 23 # atoms per molecule 6.02 x 10 23

4. Factor Label – It’s back….. How many moles are in 45.7 g of NO 2 ? 1.Ask yourself the question – Can I convert directly from grams to moles? YES – molar mass has a unit of grams/mole 2. Calculate Molar Mass of NO 2. 7 N 14.00674 8 O 15.9994 Molar mass = 14.01 g + 2(16.00 g) = 46.01 g Molar mass = 14.01 g + 2(16.00 g) = 46.01 g 3. Form conversion factors. 1 mole 46.01 g 1 mole 4. Start with your “given” from the original problem. 45.7 g NO 2 1 x 5. Use conversion factor that will allow you to “cancel” out grams and give you moles. 6.Cancel out units and calculate using significant digits. 46.01 g NO 2 1 mole =0.993 mole NO 2

5. Factor Label – It’s back….. How many atoms are in 10.0 moles of Iron (Fe)? 1.Ask yourself the question – Can I convert directly from moles to atoms? YES – there are 6.02 x 10 23 atoms = 1 mole 3. Form conversion factors. 1 m0le 6.02 x 10 23 atoms 4. Start with your “given” from the original problem. 10.0 moles Fe 1 x 5. Use conversion factor that will allow you to “cancel” out moles and give you atoms. 6.Cancel out units and calculate using significant digits. 1 mole Fe 6.02 x 10 23 Fe atoms = 6.02 x 10 24 Fe atoms 6.02 x 10 23 atoms 1 mole

6. Factor Label – It’s back….. How many molecules are in 12.1 g of H 2 SO 4 ? 1.Ask yourself the question – Can I convert directly from grams to molecules? NO – You will need two conversion factors. Grams to moles and moles to molecules. 2. Calculate Molar Mass of H 2 SO 4. 1 H 1.00794 8 O 15.9994 Molar mass = 2(1.01) + 32.07 + 4(16.00 g) = 98.09 g Molar mass = 2(1.00)g + 32.00 g + 4(16.00) g = 98.09 g. 3. Form conversion factors. 1 mole 98.09 g 1 mole 4. Start with your “given” from the original problem. 12.1 g H 2 SO 4 1 x 5.Use conversion factors that will allow you to “cancel” out grams and give you moles and moles to give you molecules. 6.Cancel out units and calculate using significant digits. 98.09 g H 2 SO 4 1 mole = 7.42 x 10 22 molecules H 2 SO 4 16 S 32.066 6.02 x 10 23 molecules 1 mole 1 mole. 6.02 x 10 23 molecules x 1 mole 6.02 x 10 23 molecules

7. Factor Label – It’s back….. How many atoms are in 210.0 g of H 2 SO 4 ? 1.Ask yourself the question – Can I convert directly from grams to atoms for a molecule? NO – You will need three conversion factors. Grams to moles, moles to molecules and molecule to atoms. 2. Calculate Molar Mass of H 2 SO 4. 1 H 1.00794 8 O 15.9994 Molar mass = 2(1.01) + 32.07 + 4(16.00 g) = 98.09 g Molar mass = 2(1.00)g + 32.00 g + 4(16.00) g = 98.09 g. 3. Form conversion factors. 1 mole 98.09 g 1 mole 4. Start with your “given” from the original problem. 210.0 g H 2 SO 4 1 x 5.Use conversion factors that will allow you to “cancel” out grams and give you moles and moles to give you molecules. 6.Cancel out units and calculate using significant digits. 98.09 g H 2 SO 4 1 mole = 9.022 x 10 24 atoms H 2 SO 4 16 S 32.066 6.02 x 10 23 molecules 1 mole 1 mole. 6.02 x 10 23 molecules x 1 mole 6.02 x 10 23 molecules How do we go from molecules to atoms? Count the number of atoms in one molecule of sulfuric acid. 2H + 1 S + 4 O = 7 atoms in 1 molecule of H 2 SO 4 so….. 1 molecule H 2 SO 4 7 atoms 7 atoms. 1 molecule H 2 SO 4 x 7 atoms H 2 SO 4

8. What conditions need to exist to use the conversion 1 mole – 22.4 L? Standard Temperature and Pressure - STP Standard Temperature Standard Pressure 0 o C 1 atm or 760 torr or 101.3 KPa At these conditions 1 mole of any gas has a volume of 22.4 L. *We will learn how to convert gases at other conditions in the Gas Law Unit.

9. Factor Label – It’s back….. How many molecules are in 15.7 L of Iron(II) Oxide? 1.Ask yourself the question – Can I convert directly from liters to molecules? NO – you will need two conversion factors. Liters to mole and mole to molecules 2. Form conversion factors. 1 m0le 6.02 x 10 23 molecules 3. Start with your “given” from the original problem. 15.7 L FeO 1 x 4. Use conversion factor that will allow you to “cancel out moles and give you atoms. 5. Cancel out units and calculate using significant digits. 22.4 L FeO 1 mole FeO = 4.22 x 10 23 FeO molecules 6.02 x 10 23 molecules 1 mole 22.4 L 1 mole x 6.02 x 10 23 molecules FeO 1 mole FeO