76 v cu2aq 2e cus eo 034 v

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Unformatted text preview: = +0.76 V Cu2+(aq) + 2e- ---> Cu(s) Eo = +0.34 V --------------------------------------------------------------Cu2+(aq) + Zn(s) ---> Zn 2+(aq) + Cu(s) Eo (calc’d) = +1.10 V 11 12 Standard Redox Potentials, Eoo Standard Redox Potentials, E oxidizing ability of ion Eo (V) Cu2+ + 2e- Cu 9 Cu +0.34 2 H+ + 2e- H2 0.00 Zn -0.76 Zn2+ + 2e- reducing ability of element Any substance on the right will reduce any substance higher than it on the left. • Zn can reduce H+ and Cu2+. • H2 can reduce Cu 2+ but not Zn2+ • Cu cannot reduce H + or Zn2+. Using Standard Potentials, Eo Using 13 Table 21.1 Eo for a Voltaic Cell Eo for a Voltaic Cell Eo for a Voltaic Cell Eo for a Voltaic Cell Volts • Which is the best oxidizing agent: O2, H2O2, or Cl2? _________________ Cd Fe Salt Bridge Volts • Which is the best reducing agent: Cd Hg, Al, or Sn? ____________________ Cd2+ • In which direction does the following Cd --> Cd2+ + 2eor Cd2+ + 2e- --> Cd reaction go? Cu(s) + 2 Ag +(aq) ---> Cu 2+(aq) + 2 Ag(s) E˚ and G? Fe --> Fe2+ + 2eor Fe2+ + 2e- --> Fe YES! • Balanced half-reactions can be added together to get overall, balanced equation. Fe Salt Bridge Fe2+ 16 Calculating Cell Voltage Calculating Cell Voltage 14 Cd2+ Fe2+ From the table, you see • Fe is a better reducing agent than Cd • Cd2+ is a better oxidizing agent than Fe2+ Overall reaction Fe + Cd2+ ---> Cd + Fe2+ ---> Eo = +0.04 V Michael Faraday Michael Faraday 1791-1867 1791-1867 Originated the terms anode, cathode, anion, cat...
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This note was uploaded on 10/19/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.

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