1. Lecture 253/27/06 Bottle and Can drive today 11-3 Hagan Info Booth Seminar today at 4 pm

2. Displacement reactions Some metals react with acids to produce salts and H 2 (g) Balance the following displacement reaction: Zn (s) + HBr (aq)  ZnBr 2 (aq) + H 2 (g)

3. voltaic or galvanic cell electrolytic cell Electrochemical cells

4. Requires Electrodes Salt bridge External circuit

5. Anode: Cathode: Net reaction: Electrochemical cell notation:

6. Electromotive force (emf) Cell potential Cell voltage

7. All other potentials determined from the SHE Zn (s)  Zn 2+ (aq, 1 M) + 2e - E° ox = ? 2 H 3 O + (aq, 1 M) + 2e -  H 2 (g, 1 atm) + 2 H 2 O E° red = 0 V__ Zn (s) + 2 H 3 O +  Zn 2+ + H 2 + 2 H 2 O E° cell = +0.76 V

8. For any reaction: E° ox = - E° red

9. Standard Reduction Potentials (25° C) E° F 2 (g) + 2e - ↔ 2F - +2.87 Au 3+ + 3e - ↔ Au (s)+1.50 Cl 2 (g) + 2e- ↔ 2 Cl - +1.36 O 2 (g) + 4 H + + 4e - ↔ 2 H 2 O+1.23 Hg 2+ + 2e - ↔ Hg (l)+0.85 Ag + + e - ↔ Ag (s)+0.80 Fe 3+ + e - ↔ Fe 2+ +0.77 Cu 2+ + 2 e - ↔ Cu (s)+0.34 Sn 4+ + 2e - ↔ Sn 2+ +0.15 2H + + 2 e - ↔ H 2 (g) 0.00 Pb 2+ + 2e - ↔ Pb (s)-0.13 Sn 2+ + 2e - ↔ Sn (s)-0.14 Ni 2+ + 2e - ↔ Ni (s)-0.26 Zn 2+ + 2 e - ↔ Zn (s)-0.76 Cr 2+ + 2 e - ↔ Cr (s)-0.91 Mg 2+ + 2 e - ↔ Mg (s)-2.37 Na + + e - ↔ Na (s)-2.71 Ca 2+ + 2 e - ↔ Ca (s)-2.87 Li + + e - ↔ Li (s)- 3.04