Units of Delta G with different equations?

[Chem_Mod]

When solving for there are a few equations you can use like -RT ln K and -nFE. But the first one gives you units of J/mol and the second only J. How can this be? (R=J/K*mol T=K and ln K is unitless. n= mol F = C/mol E= J/C)

[Chem_Mod]

Free energy can have units of J or J/mol depending on whether it is referring to the molar free energy of a substance or the free energy of a specific amount. The units of your answer will depend on the question being asked. -nFE gives energy per a substance, and -RTlnK gives energy per a mole of substance. In fact, R equals F times Avogdro's number.