Electrochemistry
colored beakers
Electrochemistry Practice Test  
Interactive Quizzes (OSU)  
Norton animated tutorials with practice problems
    - Zinc Copper Cell
    - Free Energy
    - Cell Potential
    - Alkaline Battery
    - Fuel Cells
   
Finding the Reaction Quotient (Q) - maybe more than you wanted to know...but if you've ever wondered about mixing concentrations and pressures in the Nernst equation, this is helpful