1. Molar (Formula) Mass Molar (Formula) Mass

2. Where do we find the atomic mass? For every 1 mol, there are 22.99g!

3. Molar Mass Molar (Formula) Mass – mass of a molecule Units: g/mol “grams per mol”

4. Example 1 Is the molecule ionic or covalent? Name the molecule: Molecule = NaCl (metal and nonmetal) No prefixes for ionic Ionic Sodium Chloride

5. Example 1 # A atoms in molecule x atomic mass of A # B atoms in molecule x atomic mass of B Add those numbers Molecule = NaCl NaNa 1 x 22.99 g/mol 1 58.4 g/mol Cl x 22.99 g/mol + = 35.45 g/mol

6. Example 2 Is the molecule ionic or covalent? Write the formula: Molecule = Dihydrogen Monoxide (nonmetals)Covalent H2OH2O

7. Example 2 # A atoms in molecule x atomic mass of A # B atoms in molecule x atomic mass of B Add those numbers Molecule = H 2 O H2 x 1.01 g/mol 1 18.o2 g/mol O x 2.02 g/mol + = 16.00 g/mol

8. Example 3 Is the molecule ionic or covalent? Name the molecule: Molecule = (NH 4 ) 2 O (has a polyatomic ion) Made up of ions: NH 4 + and O 2- Ionic Ammonium Oxide

9. Example 3 Molecule = (NH 4 ) 2 O N: 2 x 14 = 28 H: 8 x 1 = 8 O: 1 x 16 = 16 (NH 4 ) 2 O: 52 g / mol

10. Example 4 Is the molecule ionic or covalent? Write the formula: Molecule = Beryllium Hydroxide (has a polyatomic ion)Ionic Be(OH) 2 Made up of ions: Be 2+ and OH -

11. Example 4 Molecule: Be(OH) 2 Be: 1 x 9.01 g/mol O: 2 x 16 = 32 g/mol Be(OH) 2 = 43.03 g/mol H: 2 x 1.01 = 2.02 g/mol

12. Group Practice Check your answers when done Chemical FormulaMolar Mass KF Na 3 PO 4 Al 2 (CO 3 ) 3 Ca(SCN) 2 Iron (III) Oxide Dicarbon Tetrafluroide Lead (II) Chromate Boron Sulfate

13. Practice by Yourself In your notes, find the molar mass of: 1.H 2 O 2 2.NaNO 3 3.H 2 S 4.(NH 4 ) 2 S 5.Ca 3 (PO 4 ) 2 6.Mg(NO 3 ) 2 7.Lithium Nitride 8.Trinitrogen Pentabromide 9.Iron (III) Nitrate 10.Ammonium Carbonate