1. Materials: Structures & Uses The Mole + Quiz Part B

2. C.1Keeping Track of Atoms Balanced chemical equation To balance an equation: you can add more molecules You cannot change the molecules Cu + O 2  CuO (when we did this experiment should our mass have increased or decreased?)

3. Balancing Chemical Equations Steps 1.Get an unbalanced equation 2.Draw boxes around each chemical formula 3.Make an element inventory 4.Write Coefficients in front of the boxes until the inventory for each element is the same both before and after the reaction H 2 O  H 2 + O 2

4. Entry Task Balance this chemical equation WO 3 + H 2  W + H 2 O 1.Draw boxes around each chemical formula 2.Make an element inventory 3.Write Coefficients in front of the boxes until the inventory for each element is the same both before and after the reaction

5. Have out: Part B Quiz Review #2 Balancing Chemical Equations Worksheet #1 C.4 problems 1-6

6. Part B Quiz When done, Work on Balancing Chemical Equations Worksheet

7. C.5 The Mole A Mole A unit such as pair (2) or dozen (12) 6.02 x 10 23 602, 000, 000, 000, 000, 000, 000, 000 Chemists count atoms and molecules in moles because atoms and molecules are REALLY SMALL

8. C.5 Molar Mass The mass of one mole of anything is its atomic weight in grams!!! What is the molar mass of CO 2 ? Carbon + Oxygen + Oxygen 12.01 + 16.00 + 16.00 = 44.01 grams/mol

9. C.6 Molar Masses Finish calculating the molar mass for problems 1-9 Use the periodic table in your book

10. Homework: Balancing Chemical Equations Worksheet #1 C.5 Supplement: Molar Masses Review the Concepts Questions 1-4 (all parts) pg 180