1. ELECTROCHEMISTRY

2. What is Electrochemistry?  NaCl + AgBr   Na + CaCl 2   In which reaction to do elements change charges? How could this happen?  Rxn 2  electrons transfer from 1 element to another

3. What is Electrochemistry?  Branch of chemistry that deals with electricity- related applications of oxidation-reduction reactions (REDOX reactions)  REDOX (Reduction-Oxidation Reactions): reactions in which elements undergo changes in oxidation number as a result of electron transfer

4. Definitions  What is Reduction?  When an atom or ion GAINS one or more electrons Na + + 1e -  Na  The charge of this atom/ion will be reduced  This atom/ion also called the oxidizing agent

5. Definitions  What is Oxidation?  When an atom or ion LOSES one or more electrons Cu  Cu 2+ + 2 e -  The charge of this atom/ion will increase  This atom/ion also called the reducing agent

6. O I L R I G XIDATIONXIDATION SO S of e - EDUCTIONEDUCTION SA I N of e -

7. Identify oxidation and reduction  Must assign oxidation numbers.  Always assign the most electronegative element first, with its typical charge.  Pure elements have an oxidation number of zero. Fe 2 O 3 + CO  Fe + CO2

8. Identify oxidation and reduction CO + I 2 O 5  CO 2 + I 2 Reduced: ____________Oxidized: _____________ H 2 + O 2  H 2 O Reduced: ___________ Oxidized: ____________ Al + Fe 2 O 3  Al 2 O 3 + Fe Reduced: ___________ Oxidized: ____________

9. Identify oxidation and reduction S 8 + NO 3 ¯  SO 3 2- + NO Reduced: ________ Oxidized: __________ Mn 2+ + BiO 3 ¯  Bi 3+ + MnO 4 ¯ Reduced: _________ Oxidized: ____________

10. Applications of Electrochemistry  Electroplating https://www.youtube.com/watch?v=ctL6Oc0STUU https://www.youtube.com/watch?v=ctL6Oc0STUU  Layering a metal of atoms over the surface of another metal Car bumpers Pennies  Metal processing  Extracting Al 3+ ions from the soil and turning it into pure Al metal  Batteries https://www.youtube.com/watch?v=ksxSOwA933M https://www.youtube.com/watch?v=ksxSOwA933M  Converts chemical energy to electrical energy using electrochemical cells

11. Voltaic Cell

12.  use spontaneous oxidation-reduction reactions to convert chemical energy into electrical energy.  practical application: batteries

13. Batteries