2. Molar Mass

3.  The Mass of 1 mole (in grams)  Equal to the numerical value of the average atomic mass (get from periodic table) 1 mole of C atoms= 12.0 g 1 mole of C atoms= 12.0 g 1 mole of Mg atoms =24.3 g 1 mole of Cu atoms =63.5 g Molar Mass

4. Other Names Related to Molar Mass  Molecular Mass/Molecular Weight: If you have a single molecule, mass is measured in amu’s instead of grams. But, the molecular mass/weight is the same numerical value as 1 mole of molecules. Only the units are different. (This is the beauty of Avogadro’s Number!)  Formula Mass/Formula Weight: Same goes for compounds. But again, the numerical value is the same. Only the units are different.  THE POINT: You may hear all of these terms which mean the SAME NUMBER… just different units

5. Find the molar mass (usually we round to the hundredths place) Learning Check! A.1 mole of Br atoms B.1 mole of Sn atoms =79.90 g/mole = 118.69 g/mole

6. Mass in grams of 1 mole equal numerically to the sum of the atomic masses 1 mole of CaCl 2 = 111.1 g CaCl 2 /mol CaCl 2 1 mole Ca x 40.1 g Ca/mol Ca + 2 moles Cl x 35.5 g Cl/mol Cl = 111.1 g/mol CaCl 2 1 mole of N 2 O 4 = ? = 92.0 g/mol Molar Mass of Molecules and Compounds

7. A. Molar Mass of K 2 O = ? Grams/mole B. Molar Mass of antacid Al(OH) 3 = ? Grams/mole Learning Check!

8. Prozac, C 17 H 18 F 3 NO, is a widely used antidepressant that inhibits the uptake of serotonin by the brain. Find its molar mass. Learning Check

9. molar mass Grams Moles Calculations with Molar Mass

10. Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 3.00 moles of Al? Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 3.00 moles of Al? 3.00 moles Al ? g Al Converting Moles and Grams

11. 1. Molar mass of Al1 mole Al = 27.0 g Al 2. Conversion factors for Al 27.0g Al or 1 mol Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al 1 mol Al 27.0 g Al 3. Setup3.00 moles Al x 27.0 g Al 1 mole Al Answer = 81.0 g Al

12. The artificial sweetener aspartame (Nutra-Sweet) formula C 14 H 18 N 2 O 5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame? The artificial sweetener aspartame (Nutra-Sweet) formula C 14 H 18 N 2 O 5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame? Learning Check!

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

14. Atoms/Molecules and Grams How many atoms of Cu are present in 35.4 g of Cu? 35.4 g Cu 1 mol Cu 6.02 X 10 23 atoms Cu 63.5 g Cu 1 mol Cu = 3.4 X 10 23 atoms Cu

15. Learning Check! How many atoms of K are present in 78.4 g of K?

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

17. Learning Check! How many atoms of O are present in 78.1 g of oxygen? 78.1 g O 2 1 mol O 2 6.02 X 10 23 molecules O 2 2 atoms O 32.0 g O 2 1 mol O 2 1 molecule O 2