Answer:
It will take 3.3 s for [NOCl] to decrease to 0.042 M.
Explanation:
Integrated rate law for this second order reaction-
[tex]\frac{1}{[NOCl]}=kt+\frac{1}{[NOCl]_{0}}[/tex]
where, [NOCl] is concentration of NOCl after "t" time, [tex][NOCl]_{0}[/tex] is initial concentration of NOCl and k is rate constant.
Here, [tex][NOCl]_{0}[/tex] = 0.076 M, k = 3.2 [tex]M^{-1}s^{-1}[/tex] and [NOCl] = 0.042 M
So, [tex]\frac{1}{0.042M}=[3.2M^{-1}s^{-1}\times t]+\frac{1}{0.076M}[/tex]
or, t = 3.3 s
So, it will take 3.3 s for [NOCl] to decrease to 0.042 M.