# Atkins' Physical Chemistry 10th edition Question on steady-state approximation

Please help me with Example 20E.2 of Atkins' Physical Chemistry 10th edition textbook on using the steady-state approximation. I have attached my attempt but am just not sure how to get to the final answer.

• Your equations 1 , 2 and 3 are correct so your method is correct but you have not finished and need to substitute for NO3 in your final line then you will have your answer. – porphyrin May 13 '18 at 7:53
• exactly. $\ce{NO3}$ is an intermediate so it can't appear in the rate law. – Neil Chowdhury Jun 14 '18 at 0:17