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Chapter 8 (CIC) and Chapter 20 (CTCS). Read in CTCS Chapter 20.3 Problems in CTCS: 20.13, 15. H 2 + 1 / 2 O 2 H 2 O. Can this be done w/o combustion problems? Can this be done w/o the elements coming in contact with each other?. Anode. Cathode. Fuel Cell.
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Chapter 8 (CIC) and Chapter 20 (CTCS) • Read in CTCS Chapter 20.3 • Problems in CTCS: 20.13, 15
H2 + 1/2 O2 H2O • Can this be done w/o combustion problems? • Can this be done w/o the elements coming in contact with each other? Anode Cathode
Fuel Cell • H2 2 H+ + 2 e- oxidation / anode • 2H+ + 2e- + ½O2 H2O reduction / cathode • Combustion of H2 without flame or much heat • No NOx • Can use renewable resource (CH3OH) • No moving parts in engine – less maintenance and noise • Little heat so less energy is wasted – less CO2 per unit of energy required • Specialized Voltaic cell (uses conventional combustible fuels)
H2O(l) + CH3OH(aq) CO2(l) + 6H+(aq) + 6e- 6H+(aq) + 6e- + 3/2O2(g) 3H2O(l) CH3OH(aq) + 3/2O2(g) CO2(l) + 2H2O(l) Q: Which is the anode and which is the cathode? • The difference in the electrode potential is measured in volts • Rate of e- flow is current and is measured in amps
Voltaic Cells • Transfer of e- takes place through external pathway • Cu(s) + 2 Ag+(aq) Cu2+(aq) + 2 Ag(s) • The Cu strip loses mass while the copper solution gets more blue • The Ag strip gains mass • The ½ cells are as follows: • Cu(s) Cu2+(aq) + 2 e- • 2 e- + 2 Ag+(aq) 2 Ag(s) • Why is a salt bridge necessary?
Voltaic Cell • Why is a salt bridge necessary? • Why is the anode labeled (-) and the cathode (+)?