Chapter 21 - Electrochemistry: Quantitative Calculations

At Equilibrium

• G^o=-nFE
• G^o=-RTlnK
• lnK=(nFE^o)/RT
• (RT)/(nF)=0.02569 J/C at 25oC

Galvanic cells are not at equilibrium

• G=-RTln(K/Q)=-RTlnK + RTlnQ
• G=G^o + RTlnQ
• E=E^o-[(RT)/(NF)]lnQ

Interesting things to calculate:

• Given E^o, calculate the equilibrium constant.
• Given E, calculate the concentration of ions in the cell.
• Given the concentration of ions in the cell, calculate E.

Things to Consider

• How can Le Châteliers principle help explain the size/sign of E?
• What does the value E^o say about the size of the equilibrium constant?
• How should E^o be constructed to calculate the equilibrium constant for a reaction?

Problems

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