Do Now When the bell rings After the bell (2 min) In your seat: With pen/pencil With Notebook With Handout Packet from last class on your desk Silent and ready for Do Now Answer the following riddle: What occurs once in a minute, twice in a moment and never in one thousand years? A: The letter M Still needs Do Now

Agenda  Do Now (5 min) Warm Up (15 min) Exit Slip (3 min) Notes: Redox Reactions (20 min) Independent Practice (15 min) Activity: Electrochemical Cells (15 min) Closeout (2 min) 

1. What would the products of the following single replacement reaction be? 2Al + 6HCl  2H2 + AlCl 3H2 + 2AlCl3 Cl2 + AlH3 No reaction will take place 2. What would the products of the following reaction be? Li2O + Ba  2Li + BaO O2 + LiBa 2Li + Ba2O Warm Up In your small groups: 10 minutes Predict the Products Answer on worksheet

Warm Up What would the products of the following single replacement reaction be? 2Al + 6HCl  What would the products of the following reaction be? Li2O + Ba  In your small groups: 5 minutes Predict the Products Answer on worksheet

Exit Slip What? (5 min) How? C – No talking H – Raise hand A – Taking exit slip M – In seat P – Completing exit slip without notes and turning in If you finish early, summarize what you learned at the bottom of your notes OR answer today’s guiding question

Redox Reactions Objectives: Identify a redox reaction Identify the species that is oxidized/reduced Describe the working of electrochemical cells

Guiding Question How does your cell phone battery work?

Pardon the Interruption Unit 4 Test is: Tuesday (A – Day) Wednesday (B Day) Covers: Types of Reactions Balancing Equations Activity Series (Last Class) Redox (TODAY!!!!) There is no in-class review day Pardon the Interruption

Vocabulary and Definitions Oxidation Number: a positive or negative number assigned to each atom in a compound to help keep track of the electrons in a chemical reaction. Elements are zero. Oxidation: the loss of one or more electrons by a substance. Reduction: the gain of one or more electrons by an atom, molecule or ion, resulting in a greater negative charge. Electrochemical cell: a system that produces an electric current through an oxidation-reduction reaction.

Reduction - Oxidation Reactions Often referred to as “Redox” Any chemical reaction where the oxidation number of a molecule, atom or ion changes Example: Fe + O2  Fe2O3 ON: 0 ON: +3 ON: 0 ON: -2

Oxidation Numbers 4 Rules for Oxidation Numbers in chemical reactions The Rules: The oxidation number of an individual element is 0 The oxidation number of an element in a compound is equal to the number of electrons lost or gained The oxidation numbers of atoms in a compound add up to 0 The oxidation number of an ion is equal to its charge (Na+, SO4-2) Oxidation Numbers 4 Rules for Oxidation Numbers in chemical reactions

Rule #1 No matter the element, when it is alone in a chemical equation it is neutral Examples: Na: 0 O2: 0 2Pt: 0 The oxidation number of an individual element is 0

ON of elements in compounds = the number of electrons lost/gained by each element Examples: Rule #2 The oxidation number of an element in a compound is equal to the number of electrons lost or gained NaCl BeF2

If I add up the charges in a compound, the total sum will be 0 Examples: Rule #3 The oxidation numbers of atoms in a compound add up to 0 NaCl BeF2

Rule #4 ON of ions = charge Examples: Na+ = +1 SO4-2 = -2 The oxidation number of an ion is equal to it’s charge

Determine the oxidation numbers of the elements in the following reactions: Cl- H2 7Sn Fe2+ HBr C.F.U. Provide the oxidation numbers for the following

Identifying Reduction/Oxidation Lose electrons = oxidation Ex: 0  +1 Gain electrons = reduction Ex: 0  -1 LEO the lion says GER Increase in oxidation number Decrease in oxidation number

Identifying Reduction/ Oxidation Na  Na+ S  S-2 Be + F2  BeF2 Ba + I2  BaI2 Identify oxidation or reduction Remember: LEO says GER

Identifying Redox Reactions Is the oxidation # of an element on the reactant side different than the oxidation # on the product side?? Examples: Fe + O2  Fe2O3 NaCl + LiI  NaI + LiCl Identifying Redox Reactions How do you know if a reaction is Redox?????

CFU: Identifying Redox Reactions Is the oxidation # of an element on the reactant side different than the oxidation # of an element on the product side?? You Do: H2 + O2  H2O Cl2 + NaBr  NaCl + Br2 LiBr + CaO  Li2O + CaBr2 CFU: Identifying Redox Reactions Identify if the three reactions are redox reactions.

Activity: How it Works How? What? Answer: What is a battery? C: 0-1, no conversation unless you are the speaker H: Raise hand A : Read pages 384-386 & answer questions M: None, in seat P: Reading along, reading aloud when called on, thinking through the questions, taking notes, answering questions Answer: What is a battery? How does a battery work? Give an example of a wet cell battery AND a dry cell battery

Electrochemical Cells Created by Redox reactions 2 Types Galvanic (aka Voltaic) Cell Ex: Non- rechargeable batteries Electrolytic Cell Ex: Rechargeable batteries (while charging)

Independent Practice What How 15 minutes C: 0 – 1, only on task conversation H: Raise hand, move on to next question until I am available A: Completing Redox Questions M: None, in seats. 3 Hall passes. P: Answering questions on the handout, using notes 15 minutes Q1: Identify as Oxidation or Reduction Q2: Identify which is oxidized and reduced Q3-9: Answer M.C.

Exit Slip What? (5 min) How? C – No talking H – Raise hand A – Taking exit slip M – In seat P – Completing exit slip without notes and turning in If you finish early, summarize what you learned at the bottom of your notes OR answer today’s guiding question

Closing Don’t forget to stretch One thing you learned today Remember: Unit 4 test next week Study guide due before test Honor’s: Research Plan & Experiment Design due TODAY!!!!!