1. THE MOLE THURSDAY, 1/7

2. WHAT IS A MOLE? 1 mole of a substance is 6.02 x 10 23 representative particles. Avogadro’s number = 6.02 x 10 23 Avogadro determined the difference between atoms and particles. Representative particle: the “species” present in a substance (usually atoms, molecules or formula units)

3. KEY POINT!!! A mole of any substance contains Avogadro’s number of representative particles, or 6.02 x 10 23 representative particles. Practice  How many molecules are in one mole of Hydrogen?  How many atoms are in three moles of hydrogen?

5. REPRESENTATIVE PARTICLES AND MOLES A mole of any substance contains Avogadro’s number of representative particles, or 6.02 x 10 23 representative particles. SubstanceRepresentative particle Chemical formulaRepresentative particles in 1.00 mole Atomic nitrogenAtomN6.02 x 10 23 Nitrogen gasMoleculeN2N2 6.02 x 10 23 WaterMoleculeH2OH2O6.02 x 10 23 Calcium ionIonCa 2+ 6.02 x 10 23 Calcium flourideFormula unitCaF 2 6.02 x 10 23 SucroseMoleculeC 12 H 22 O 11 6.02 x 10 23

6. ATOMIC MASS Atomic mass of an element (the mass of a single atom) is expressed in atomic mass units (amu) Atomic masses are relative values based on the mass of carbon-12

7. MOLAR MASS The atomic mass of an element expressed in grams is the mass of a mole of the element. The mass of a mole of an element is its molar mass. Expressed in grams per mole (g/mol).

9. THE MASS OF A MOLE OF A COMPOUND To calculate the molar mass of a compound, 1.find the number of grams of each element in one mole of the compound. 2.Then add the masses of the elements in the compound.

10. THE MOLAR MASS OF WATER

11. MOLAR MASS OF A COMPOUND Find the molar mass of glucose (C 6 H 12 O 6 )

12. Magnesium is a light metal used in the manufacture of aircraft, automobile wheels, tools and garden furniture. How many moles of magnesium is 1.25 x 10 23 atoms of magnesium? CONVERTING # OF ATOMS TO MOLES

13. Propane is a gas used for cooking and heating. How many atoms are in 2.12 mol of propane (C 3 H 8 )? CONVERTING MOLES TO NUMBER OF ATOMS

14. CONVERTING MOLES TO MASS What is the mass of 9.45 mol of aluminum oxide (Al 2 O 3 )?