Answer:
Overall: [tex]NO_{2}+CO\rightarrow NO+CO_{2}[/tex]
Explanation:
Overall reaction is a combination of step 1 and step 2. The overall reaction is obtained as follows:
Step 1: [tex]NO_{2}+NO_{2}\rightarrow NO+NO_{3}[/tex]
Step 2: [tex]NO_{3}+CO\rightarrow NO_{2}+CO_{2}[/tex]
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Overall: [tex]NO_{2}+CO\rightarrow NO+CO_{2}[/tex]
Here, [tex]NO_{3}[/tex] is produced in the first step and subsequently consumed in second step. Hence, [tex]NO_{3}[/tex] is an intermediate in this reaction.
Intermediates are not involved in overall reactions. Here, also, the overall reaction does not contain [tex]NO_{3}[/tex].