The predicted rate law is rate = k [NO] [03]. Identify the rate determining step. Write the overall reaction.

Question

A complex reaction take place in two steps 

(i) NO (g) + O₃ (g) \(\longrightarrow \) NO₃ (g) + O (g)

(ii) NO₃ (g) + O (g) \(\longrightarrow \) NO₂ (g) + O₂ (g) 

The predicted rate law is rate = k [NO] [0₃]. Identify the rate determining step. Write the overall reaction. Which is the reaction inter mediate? Why?

Answer 1

NO (g) + O₃ (g) \(\longrightarrow \) NO₃ (g) + O (g)  ..........(i)

NO₃ (g) + O (g) \(\longrightarrow \) NO₂ (g) + O₂ (g)  ..........(ii)

As given,

rate of reaction = K [NO] [O₃]

it means, rate of reaction depends on the only (concentration) or partial pressure of NO and O₃.

Therefore, the first reaction is a rate determining step.

On adding equation (i) and (ii) we get overall reaction.

NO (g) + O₃ (g) \(\longrightarrow \) NO₂ (g) + O₂ (g) 

And reaction intermediate are NO₃ (g) + O (g)