Final answer:
CO is not a catalyst in the reaction between NO2 and CO because it is a reactant that is consumed in the reaction, and the rate of the reaction is independent of the concentration of CO. The rate of the reaction is determined by the concentration of NO2, which is second order, while the reaction is zero order in CO.
Step-by-step explanation:
The reaction rate being independent of the concentration of CO indicates that CO is not a catalyst for the reaction. The correct answer option is D. CO is not a catalyst of the reaction since it is a reactant and is consumed in the reaction. A catalyst by definition is a substance that increases the rate of a chemical reaction without undergoing any permanent chemical change. In the given chemical reaction, CO is consumed, and hence cannot be considered a catalyst. Moreover, the rate of the reaction is determined by the concentration of NO2 and is independent of the concentration of CO, which means CO's presence does not alter the speed of the reaction, further disqualifying it as a catalyst. The rate law for the reaction is given by rate = k[NO2]2, confirming that the reaction rate is second order in NO2 and zero order in CO.