Nitrogen monoxide is a pollutant in the atmosphere that is produced in car engines by an endothermic reaction between nitrogen and oxygen. $\text{N}_2(g) + \text{O}_2(g) \rightarrow 2\text{NO}(g) \qquad \Delta H = +66\,\text{kJ mol}^{-1}$ Which labelled diagram shows the correct energy profile for this reaction?
Chemistry 9701 · AS & A Level · Chemical energetics