1. Catalyst – April 4+8-13+5, 2013 HW OUT! GRAB A CALCULATOR! 1. How many grams are in 4.5 moles of CaBr 2 ? (Hint: use MOLAR MASS) 2. How many moles are in 3 x 10 24 atoms of Lithium? (Hint: use AVOGADRO’S #)

2. Today’s Agenda  Catalyst  Ion Game!  Molar Conversion Review (20 min)  Balancing Chemical Equations Part 1  Practice! Practice! Practice!  Exit Question HW: To Be Determined!!!

3. Yesterday’s Exit Question 1. What information do we get from Avogadro? 1 mole = 6.02 x 10 23 particles How to convert between moles and atoms 2. What is the molar mass of Helium? 4.00 g/mol

4. Today’s Objectives  SWBAT apply the Law of Conservation of Matter to chemical equations.  SWBAT balance simple chemical equations.

5. LESSON TITLE: BALANCING CHEMICAL EQUATIONS (Part 1)

7. 4 minutes! PARTNER WORK!

8. Let’s Look at a Chemical Reaction 1 RIGHT! WRONG!

9. Without the Coefficients…

10. With the Coefficients… 1

11. Why Balance Equations?  Key Point #1: Balancing a chemical equation refers to establishing the mathematical relationship between the quantity of reactants and products. The quantities are expressed as moles.

12. Let’s Take Another Look… 2 x 10.81 g = 21.62 g 2 x 183.84 g = 367.68 g 1 x 10.81 + 3 x 183.84 Mass Products = 562.33 g 21.62 g + 367.68 g Mass Reactants = 583.95 g NOT EQUAL!

13. Oh Heyyyy….AWESOME! BOOYA! 2 x 10.81 g = 21.62 g 6 x 183.84 g = 1103.04 g Mass Reactants and Mass of Products = 1124.66 g 1 NOT EQUAL! EQUAL!

14. L-C-M!!!  Key Point #2: Chemical reactions MUST follow the Law of Conservation of Mass/Matter, so the mass of the reactants should equal the mass of the products. The Law of Conservation of Mass/Matter (LCM) states that matter cannot be created or destroyed.

15. Balancing equations RULES!  Key Point #3: When balancing equations, never, Never, NEVER change subscripts! ONLY CHANGE COEFFICIENTS!

16. Coefficient  A coefficient is a whole number that comes in front of the compound formula, never in the middle! (stands for atoms or moles)  You multiply the coefficient to all the numbers in the compound 2 AlCl 3

17. 3 minutes! PARTNER WORK!

18. Steps to Balancing Equations 1. TAKE INVENTORY! List elements. Count on both sides. 2. BALANCE! Add coefficients and multiply. Re-count elements. 3. CHECK YOUR WORK!

19. Balancing Chemical Reactions H 2 + O 2  H 2 O __H__ __O__ Write down elements.

20. Balancing Chemical Reactions H 2 + O 2  H 2 O __H__ __O__ Count the atoms of each element.

21. Balancing Chemical Reactions H 2 + O 2  H 2 O _2_H_2_ __O__ How many “H”s are there?

22. Balancing Chemical Reactions H 2 + O 2  H 2 O _2_H_2_ _2_O_1_ How many “O”s are there?

24. Balancing Chemical Reactions Try These: N 2 + H 2  NH 3 P 4 O 10 + H 2 O  H 3 PO 4 Ca 3 P 2 + H 2 O  Ca(OH) 2 + PH 3

25. Balancing Chemical Reactions Try These: 1N 2 + 3H 2  2NH 3 P 4 O 10 + H 2 O  H 3 PO 4 Ca 3 P 2 + H 2 O  Ca(OH) 2 + PH 3

26. Balancing Chemical Reactions Try These: 1N 2 + 3H 2  2NH 3 1P 4 O 10 + 6H 2 O  4H 3 PO 4 Ca 3 P 2 + H 2 O  Ca(OH) 2 + PH 3

27. Balancing Chemical Reactions Try These: 1N 2 + 3 H 2  2NH 3 1P 4 O 10 + 6H 2 O  4H 3 PO 4 1Ca 3 P 2 + 6H 2 O  3Ca(OH) 2 + 2PH 3

28. BALANCING WORKSHEET!!! The more you do, the more you learn!

29. Exit Question  Balance ONE of the following equations: 1. __KClO 3 ---> __KCl + __O 2 2. __S + __O 2 ---> __SO 3 HW: Study Ions – Quiz tomorrow! Bring back Progress Reports!