1. February 07, 2013 AGENDA: 1 – Bell Ringer/Agenda
Today’s Goal:
Students will be able to balance chemical reactions.
Homework
Complete Balancing Classwork– due tomorrow
Complete any Week 21 late work (still turn in for partial credit by tomorrow)
Empty Organize Binder
AGENDA:
1 – Bell Ringer/Agenda
2 – Cornell Notes: Balancing Chemical Reactions
3 – Classwork Time

2. 3 MINUTES REMAINING…

3. Thursday, February 07 Objective: Bell Ringer:
Students will be able to balance chemical reactions.
Bell Ringer:
Translate the following sentence into a skeleton equation:
Silver (I) oxide reacts to form solid silver and oxygen gas

4. 2 MINUTES REMAINING…

5. Thursday, February 07 Objective: Bell Ringer:
Students will be able to balance chemical reactions.
Bell Ringer:
Translate the following sentence into a skeleton equation:
Silver (I) oxide reacts to form solid silver and oxygen gas

6. 1 minute Remaining…

7. Thursday, February 07 Objective: Bell Ringer:
Students will be able to balance chemical reactions.
Bell Ringer:
Translate the following sentence into a skeleton equation:
Silver (I) oxide reacts to form solid silver and oxygen gas

8. 30 Seconds Remaining…

9. Thursday, February 07 Objective: Bell Ringer:
Students will be able to balance chemical reactions.
Bell Ringer:
Translate the following sentence into a skeleton equation:
Silver (I) oxide reacts to form solid silver and oxygen gas

10. BELL-RINGER TIME IS UP!

11. February 07, 2013 AGENDA: 1 – Bell Ringer/Agenda
Today’s Goal:
Students will be able to balance chemical reactions.
Homework
Complete Balancing Classwork– due tomorrow
Complete any Week 21 late work (still turn in for partial credit by tomorrow)
Empty Organize Binder
AGENDA:
1 – Bell Ringer/Agenda
2 – Cornell Notes: Balancing Chemical Reactions
3 – Classwork Time

12. Thursday, February 07 Objective: Bell Ringer:
Students will be able to balance chemical reactions.
Bell Ringer:
Translate the following sentence into a skeleton equation:
Silver (I) oxide reacts to form solid silver and oxygen gas
Answer : Ag2O  Ag(s) + O2 (g)

13. Why do we balance chemical equations?
Cornell Notes
Topic: Balancing Chemical Reactions
Date: 2/07/2013
MgO  Mg + O2
Reactants  Products
Why do we balance chemical equations?
Things reacting
Things produced

14. Cornell Notes (continued)
Law of Conservation of Mass/Matter = =
Mass of reactants
Mass of products
# of each element of the reactants
# of each element of the products

15. Cornell Notes (continued)
Reactants ___ MgO Mg = 1 O = 1
Products ___ Mg + ___ O2 Mg = 1 O = 2
Example: 2 2 1
Coefficients
x 2 = 2
x 2 = 2
x 2 = 2
x 1 = 2
Balanced Chem. Eqn. =
2 MgO  2 Mg O2
= Mg
= O  +

16. Cornell Notes (continued)
“How to Balance” Steps:
Draw a line between reactants & products.
Count up all atoms of reactants & products.
Determine multiplier (coefficient)  LCD.
Place multiplier (coefficient) in front of compound, and multiply in your total.
Save balancing the H and O until LAST!
(hint: I prefer to save O until the very last)
Double-Check to make sure it is balanced!

17. Practice (on LEFT page)
Counting Atoms: O2
O = 2
Fe2O3
Fe = 2
O = 3
2 NaOH
Na = 2
O = 2
H = 2
2 Ca(NO3)2
Ca = 2
N = 4
O = 12

18. Practice (continued)
Reactants ___ Ag + ___CuCl2 Ag = 1 Cu = 1 Cl = 2
Products ___ Cu + ___ AgCl Ag = 1 Cu = 1 Cl = 1
Example: 2 1 1 2
x 2 = 2
x 2 = 2
x 1 = 1
x 1 = 1
x 1 = 2
x 2 = 2

19. Never
Never change a subscript to balance an equation (You can only change coefficients)
H2O is a different compound than H2O2
If you change the subscript (formula) you are describing a different chemical.
Never put a coefficient in the middle of a formula; they must go only in the front
2NaCl is okay, but Na2Cl is not.

20. Practice (continued) 2 4 3 Reactants ___ Al2O3 Al = 2 O = 3
Products ___ Al + ___ O2 Al = 1 O = 2
Example: 2 4 3
x 2 = 4
x 4 = 4
x 2 = 6
x 3 = 6

21. Practice Balancing Examples
_AgNO3 + _Cu ® _Cu(NO3)2 + _Ag
_Mg + _N2 ® _Mg3N2
_P + _O2 ® _P4O10
_Na + _H2O ® _H2 + _NaOH
_CH4 + _O2 ® _CO2 + _H2O 2 2 3 4 5 2 2 2 2 2