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2. Stoichiometry: Conversions At the conclusion of our time together, you should be able to: 1. Convert a mole of a chemical to particles or grams of that chemical 2. Convert grams of a chemical to moles or particles 3. Convert particles of a chemical to moles or grams

3. Molar Mass of Molecules and Compounds – Page 4 Mass in grams of 1 mole of an element or compound Numerically to the sum of the atomic masses 1 mole of NaCl =

4. Calculations with Molar Mass molar mass Grams Moles

5. Molar Mass as a Conversion Factor Molar Mass of the Compound 1 mole or 1 mole Molar Mass of the Compound

6. Examplse of Converting Moles to Grams – Page 6 1) 7.800moles of Fe 2 O 3 2) 100.2mol of Pb(NO 3 ) 2

7. Avogadro’s Number as a Conversion Factor 6.02 x 10 23 particles 1 mole or 1 mole 6.02 x 10 23 particles Note that a particle could be an atom OR a molecule!

8. Examples of Avogadro’s Number as a Conversion Factor – Page 7 1. 4.50 mole of Cu 2. 7.62 x 10 24 molecules of V

9. Atoms/Molecules to Grams Since 6.02 X 10 23 particles = 1 mole and 1 mole = molar mass (grams) You can convert atoms/molecules to moles and then moles to grams! (Two step process) You can’t go directly from atoms to grams!!!! You MUST go thru MOLES.

10. Calculations molar mass Avogadro’s number Grams Moles particles Everything must go through Moles!!!

11. Atoms/Molecules to Grams – Page 8 1) 1.806x10 24 molecules Fe = grams? 2) 1.20x10 28 molecules CuSO4 = grams?

12. Stoichiometry: Conversions Let’s see if you can: 1. Convert a mole of a chemical to particles or grams of that chemical 2. Convert grams of a chemical to moles or particles 3. Convert particles of a chemical to moles or grams

13. Learning Check! What is the mass (in grams) of 1.20 X 10 24 molecules of glucose (C 6 H 12 O 6 )? = 327 g of glucose