Problem :
Given that the free energy of formation of liquid water is -237 kJ / mol, calculate the potential for
the formation of hydrogen and oxygen from water.
To solve this problem we must first calculate ΔG for the reaction, which is
-2 ( -237 kJ / mol) = 474 kJ / mol. Knowing that ΔG = -nFE^{o} and n
= 4, we calculate the potential is -1.23 V.
Problem :
Calculate the potential of a concentration cell with anode concentration of
1 M and cathode concentration of 0.01 M at 75^{o}C.
Knowing the Nernst Equation and realizing that the temperature is not
25^{o}C, we write that: E = E^{o} - (RT/nF) ln Q
E^{o} for any concentration cell is zero so, after plugging in all the numbers we
find that: E = 0.035 V.