To change the sign of ∆G of a reaction you can change the temperature change the enthalpy change the entropy add a catalyst Calculate ∆Gº for the reaction, NO2(g)+N2O(g)→3NO(g), where ∆Gfº=51.8 kJ/mol for NO2(g), 104 kJ/mol for N2O(g), and 86.7 for NO(g): 69.1 kJ 104 kJ -69.1 kJ -104 kJ When is a reaction never spontaneous? ∆H>0, ∆S>0 ∆H 0 Keq=Q Keq<1