A coulomb (C) relates electrical potential, expressed in volts, and energy, expressed in joules. The faraday (F) is Avogadro’s number multiplied by the charge on an electron and corresponds to the cha...A coulomb (C) relates electrical potential, expressed in volts, and energy, expressed in joules. The faraday (F) is Avogadro’s number multiplied by the charge on an electron and corresponds to the charge on 1 mol of electrons. Spontaneous redox reactions have a negative ΔG and therefore a positive Ecell. Because the equilibrium constant K is related to ΔG, E°cell and K are also related. Large equilibrium constants correspond to large positive values of E°.