Final answer:
The reaction of nitrogen and oxygen to form nitrogen monoxide is spontaneous at low temperatures and nonspontaneous at high temperatures, requiring a significant amount of heat, such as lightning, to proceed.
Step-by-step explanation:
The reaction N2(g) + O2(g) → 2NO(g) has a positive ΔH° of +182.6 kJ, indicating that the reaction is endothermic. This fact, coupled with standard entropy and Gibbs free energy changes from provided examples, suggests that this reaction would be spontaneous at low temperatures but nonspontaneous at high temperatures.
To predict the exact temperature at which the reaction shifts from spontaneous to nonspontaneous, one would set ΔG° equal to zero and rearrange the equation ΔG° = ΔH° - TΔS° to solve for T. However, in this specific case, the reaction is typically nonspontaneous under normal conditions and requires high temperatures, such as those found during a lightning strike, for it to proceed.