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Electrochemistry - Oxidation and Reduction. Given the following reaction: Zn (s) + CuSO 4 ZnSO 4 + Cu. a) Identify the oxidation values for each element in the reaction. Zn (s) + CuSO 4 ZnSO 4 + Cu 0 +2 +6 -2 +2 +6 -2 0.
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Electrochemistry - Oxidation and Reduction Given the following reaction: Zn (s) + CuSO4 ZnSO4 + Cu a) Identify the oxidation values for each element in the reaction Zn (s) + CuSO4 ZnSO4 + Cu 0 +2 +6 -2 +2 +6 -2 0 b) write the oxidation half-reaction and the reduction half- reaction for the reaction oxidation: Zn Zn 2+ + 2 e - reduction: Cu 2++ 2 e- Cu
Given the following reaction: Zn (s) + CuSO4 ZnSO4 + Cu c) Identify the oxidizing agent and the reducing agent Oxidizing agent = substance reduced = Cu2+ Reducing agent = substance oxidized = Zn
Electrochemical Cell Also called a Voltaic Cell or Galvanic Cell Oxidizing and Reducing Agents are physically separated so that electrons flow between the agents through an outside conductor The oxidizing and reduction agents must also be connected by a salt bridge or semiporous barrier so that charged ions can move between the agent in order to equilibrate overall charge
Electrochemical Cell Oxidizing and Reducing Agents are separated and electrons flow between the agents through an outside conductor
Anode a) Uusally written on the left side of a diagram; b) Negative half cell - electrons formed in the anode and flow from the anode left to right c) Oxidation occurs in this half cell; contains the reducing agent Notes: Anode and oxidation both start with vowels Electrons usually flow from left to right Anode related to anions which have a neg charge
Cathode a) Usually written on the right side of a diagram b) Positive half cell; electrons move toward the cathode c) Reduction occurs in this half cell; Contains the oxidizing agent
Electrons flow from the anode to the cathode The difference in potential energy between the anode and cathode drives the electrons and is termed the electromotive force or cell potential - measured in volts volt = 1 J of work per charge
Electrons flow from the anode to the cathode. The Cell Potential ( E cell ) for this example is 1.10 Volts. Note that the value of the cell potential is positive.
At the anode, Zn is being oxidized to Zn 2+, producing 2 electrons
At the cathode, Cu 2+ is being reduced to Cu, gaining 2 electrons