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Electrochemistry Lesson 8 Electrochemical Cells. Electrochemical cells are Batteries. Alkaline Batteries. KOH. Car Batteries. Pb-Acid H 2 SO 4. Mitsubishi iMiEV - Pure Electric Car. $ 36,000 US. $ 50,000 Can. Powered by a 330 v Li-Ion Rechargeable battery.
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Electrochemistry Lesson 8 Electrochemical Cells
Car Batteries Pb-Acid H2SO4
Mitsubishi iMiEV - Pure Electric Car $ 36,000 US $ 50,000 Can Powered by a 330 v Li-Ion Rechargeable battery Plugs into your house and takes 14 hours to charge -100 km for $ 0.60 Top Speed 130 km/h 63 hp and 133 lb.-ft. of torque
Cell Phone batteries Lithium Ion Rechargeable battery
Space Ship Batteries Powered by Radioisotopes
Notes on Electrochemical Cells An electrochemical cell– a system of electrodes, electrolytes, and salt bridge that allow oxidation and reduction reactions to occur and electrons to flow through an external circuit. The salt bridgeallows ions to migratefrom one half-cell to the other without allowing the solutions to mix. 1. Spontaneous redox reaction 2. Produces electricity from chemicals 3. Is commonly called a battery
AnalyzingElectrochemical Cells The reaction that is higher on the reduction chartis the reductionand the lower is oxidation and is written in reverse.
For any cell Oxidation always occurs at the anode and reduction at the cathode Electrons flow through the wire and go from anode to cathode Anions (- ions) migrate to the anodeand cations (+ions) migrate towards the cathode usually through the salt bridge
1. Draw and completely analyze a Cu/Sn electrochemical cell. voltmeter e- e- Higher Greatest Electron Affinity Reduction Cathode Cu2+ + 2e- → Cu(s) 0.34 v Gains mass + 0.48 v Lower Oxidation Anode Sn(s)→ Sn2+ +2e- +0.14 v Loses mass - Na-+ NO3- Sn Cu Cu2+ Sn2+ NO3- NO3- Overall Reaction: Cu2+ + Sn→ Sn2+ +Cu(s)0.48 v
The Hydrogen half cellinvolves a gas and requires an inert or nonreactive Pt electrode. Wire to circuit H2(g) in H+ Cl- Pt(s) 1 M HCl
Draw a H2/Ag electrochemical cell with a KNO3 salt bridge. Pt 2e- voltmeter 2e- 0.80 v 1.0 M KNO3 Higher Greater electron affinity Reduction Cathode + Ag+ + 1e- → Ag(s) +0.80 v Gains mass Ag H2 NO3- K+ oxidation Anode - H2 → 2H+ + 2e- 0.00 v pH decreases Ag+ NO3- H+ Cl- 1 M HCl 1 M AgNO3 2Ag+ + H2 → 2Ag + 2H+ 0.80 v