I. Electrolysis

� Driving a nonspon. redox rxn with electrical current.

� Cu(s) + Zn2+(aq) à Zn(s) + Cu2+(aq)

� E° = –1.10 V

� Overpotential: excess V above V calculated w/ E° that is req’d for electrolysis.

I. Electrolysis

� Faraday’s Law: Amt. of chem. change produced proportional to the amt. of current passed through it.

� Ex. #1: How much Cu(s) can be deposited if you run a current for 3.0 min. @ 2.0 amps.

II. Predicting the Products

� Pure Molten Salts

II. Predicting the Products

� Aqueous Solutions

III. Batteries

� Dry Cell Batteries:

An: Zn(s) à Zn2+(aq) + 2 e–

Cat: 2 MnO2(s) + 2 NH4+(aq) + 2 e–

à Mn2O3(s) + 2 NH3(g) + H2O(l)

III. Batteries

� Alkaline Batteries:

� An: Zn(s) + 2 OH–(aq) à Zn(OH)2(s) + 2 e–

� Cat: 2 MnO2(s) + 2 H2O(l) + 2 e– à

2 MnO(OH)(s) + 2 OH–(aq)

III. Batteries

� Lead-Acid Batteries:

III. Batteries

� Nickel-Cadmium (NiCad)Batteries:

III. Batteries

� Nickel-Metal Hydride (NiMH)Batteries:

III. Batteries

� Lithium Ion Batteries:

III. Batteries

� Hydrogen Fuel Cells:

IV. Miscellaneous Redox

� Corrosion:

IV. Miscellaneous Redox

� Galvanizing:

PS 12.3

�Read section 17.5-17.8

�Ch. 17: #71-91(odd)