18.4 nernst equation and concentration cells

• the nernst equation is used for nonstandard conditions
• E = E° - (RT/nF)lnQ
• Q = products/reactants
• @ 298K: E = E° - (0.0257/n)lnQ
• a concentration cell contains the same material in both half-cells, but at different concentrations
• concentration cells operate until the concentrations are the same