\[\begin{align*} 2 \ce{NO} \left( g \right) &\rightarrow \cancel{\ce{N_2O_2} \left( g \right)} \\ \cancel{\ce{N_2O_2} \left( g \right)} + \ce{O_2} \left( g \right) &\rightarrow 2 \ce{NO_2} \left( g \r...2NO(g)→N2O2(g)N2O2(g)+O2(g)→2NO2(g)2NO(g)+O2(g)→2NO2(g) An intermediate is a species which appears in the mechanism of a reaction, but not in the overall balanced equation.