The thermal decomposition of N$_2$O$_5$ to form NO$_2$ and O$_2$ is a first order reaction. The rate constant for the reaction is $5.1x10^{–4}s^{-1}$ at $318^{\circ} K$. Calculate the half-life of this reaction.

Question

$\begin{array}{1 1} 1400\;s \\ 2800 \;s \\ 700\;s \\ 2100\;s \end{array}$