2.  “Mole” derives from Latin meaning “pile” or “heap”

3.  How many are in: ◦ 1 doz? ◦ 2 doz? ◦ ½ doz? ◦ ¼ doz?

4.  Carbon has a mass of 12 g  Oxygen has a mass of 16 g  H 2 O molecules has a mass of 18 g  How do these #’s relate to the atom or compound? ◦ Atomic mass

5.  Amedeo Avogadro (1776-1856)  1 mole = 6.0221415 x 10 23 ◦ Particles ◦ Molecules ◦ Atoms ◦ Ions ◦ Formula units ◦ Etc, etc

6.  If we stack 6.02 x 10 23 pennies on top of one another, the stack of pennies would reach the sun and back almost 500 million times!  AN of marbles spread over the surface of the earth would produce a layer of marbles about 50 miles thick!  If the worlds entire population of 7 billion people, counting at the rate of one per second collectively counted to AN, it would take 3 million years to get there!

7.  1 mol of Fe = 55.847 grams  1 mol H 2 = 2.016 grams  1 mol CO 2 = 12 + 16 + 16 = 44 grams  Molar mass is grams per mole ◦ Similar to miles per hour

8.  What would the mass in grams of 3.50 moles of Cu atoms be? 222 g Cu

9. 128.7g NaCl

10.  How many moles are in 6.195 grams of phosphorous? 0.200 mole of P

11.  Now, how many atoms of phosphorous would that be? 1.204 x 10 23 atoms of P ** remember 1 mol = 6.02 x 10 23 atoms**

12.  How many moles is 1.20x10 23 atom of Zn? 0.199 mol of Zn

13.  What is the mass (in grams) of 1.20 x 10 23 atoms of Zn? (use answer from last problem) 13.0 g of Zn

14.  How many atoms are in 0.750 grams of Zn? 6.90 x 10 21 atoms of Zn