Knowing that a reaction has multiple steps?

[pierce15]

Hello, is there a way to eliminate the possibility of a reaction having one single step? For example, the reaction

$$NO_2(g) + CO(g) \to NO(g) + CO_2 (g)$$

appears to me to be single stepped, but my textbook gives the reaction in multiple steps and does not elaborate on how the individual steps were found.

Also, I apologize for the triviality of this question; I'm only in high school chemistry.

 

[hilbert2]

Either intermediate compounds can be observed spectroscopically or by other means, or the reaction rate depends on the concentrations of reactants in a way that can't be explained with a single-step mechanism. This kind of questions are actually way over high school level.

 

[Yanick]

Its not a trivial question at all and it's good that you are thinking about these things. Figuring out reaction mechanisms is a huge field and relies heavily on kinetics studies and spectroscopy. Also you can infer multi step mechanisms, in certain systems, by the presence of a mixture of products due to competing rates of various side reactions possible from a given intermediate.