Date post: | 20-Jan-2016 |
Category: |
Documents |
View: | 220 times |
Download: | 0 times |
Lecture 26 3/30/07
E°
F2 (g) + 2e - ↔ 2F- +2.87
Ag+ + e- ↔ Ag (s) +0.80
Cu2+ + 2e- ↔ Cu (s) +0.34
Zn2+ + 2e- ↔ Zn (s) -0.76
Quiz
1. Consider these half-reactions1. Which is the strongest oxidizing agent?
2. Will F2(g) oxidize Ag(s) to Ag+?
3. Will Zn2+ reduce Ag+ to Ag(s)?
2. Calculate the equilibrium constant for:
Ag+ (aq) + Cu (s) ⇆ Ag(s) + Cu2+ (aq)
Kln 0257.0
En
K 298at Qlnn
0257.0EE
K 298at Qlogn
0592.0EE
1.50 amps flow through a Ag+(aq) solution for 15.0 min.
What mass of Ag metal is deposited?
The anode reaction in a lead storage battery is:
Pb(s) + HSO4-(aq) PbSO4(s) + H+(aq) + 2e-
If a battery delivers 1.50 amp, and you have 454 g of Pb, how long will the battery last?
Corrosion
http://www.gordonengland.co.uk/img/corr5.gif
http://awesomegems.com/jewelry/Cleaner-Ionic-tarnish2.jpg
E°
F2 (g) + 2e - ↔ 2F- +2.87
Au3+ + 3e- ↔ Au (s) +1.50
Cl2 (g) + 2e- ↔ 2 Cl- +1.36
O2 (g) + 4 H+ + 4e- ↔ 2 H2O +1.23
Hg2+ + 2e- ↔ Hg (l) +0.85
Ag+ + e- ↔ Ag (s) +0.80
Fe3+ + e- ↔ Fe2+ +0.77
Cu 2+ + 2 e- ↔ Cu (s) +0.34
Sn4+ + 2e- ↔ Sn2+ +0.15
2H+ + 2 e- ↔ H2 (g) 0.00
Pb2+ + 2e- ↔ Pb (s) -0.13
Sn2+ + 2e- ↔ Sn (s) -0.14
Ni2+ + 2e- ↔ Ni (s) -0.26
Zn2+ + 2 e- ↔ Zn (s) -0.76
Cr2+ + 2 e- ↔ Cr (s) -0.91
Mg2+ + 2 e- ↔ Mg (s) -2.37
Na+ + e- ↔ Na (s) -2.71
Ca2+ + 2 e- ↔ Ca (s) -2.87
Li+ + e- ↔ Li (s) - 3.04
Recap
Balancing Redox reactions Electrochemical cells Batteries Standard Reduction Potential table
Corrosion Nernst equation Electrolysis
Molten aqueous
Counting electrons
www.state.sd.us/denr/DES/mining/P000106.jpg
http://www.nelpi.org/tarcreek/slides/5s.html
Acid Mine DrainageREDOX in the real world
FeS2 (pyrite) + O2 SO42- + Fe2+