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

3 MINUTES REMAINING…

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

2 MINUTES REMAINING…

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

1 minute Remaining…

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

30 Seconds Remaining…

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

BELL-RINGER TIME IS UP!

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

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)

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

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

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 + 1 O2 = Mg = O  +

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!

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

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

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.

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

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