The rate constant for the 2nd order reaction shown below is $0.54 M^{–1}$ at 300$^{\circ}$ C. How many seconds would it take for the concentration of NO$_s$ to decrease from $0.62\; M$ to $0.28\; M$?

Question

$\begin{array}{1 1} 3.6\;s \\ 6.2\;s \\ 1.8 \;s \\ 0.9\;s \end{array}$