In an electrochemical cell, a redox reaction with a negative standard free energy change (ΔG°) is used. What is the significance of the negative ΔG° in this reaction?
1) The reaction is spontaneous and can proceed without any external energy input.
2) The reaction is non-spontaneous and requires an external energy input to proceed.
3) The reaction is at equiLiBrium and does not proceed in either direction.
4) The reaction is not feasible and cannot occur.