Free energy and Chemical Energy question

[gkangelexa]

$\Delta$G = -n F E_max

and

$\Delta$G = $\Delta$G$\circ$ + RT ln(Q)


When do we use the first equation and when do we use the second one?

 

[Mike H]

The first equation contains the Faraday constant. What sorts of chemical systems/problems would entail needing to use that?

What do the two terms on the right-hand side of the second equation represent?