The reaction of $\mathrm{NOBr}(g)$ to form $\mathrm{NO}(g)$ and $\mathrm{Br}_{2}(g)$ is second order: $$2 \mathrm{NOBr}(g) \longrightarrow 2 \mathrm{NO}(g)+\mathrm{Br}_{2}(g)$$ The rate constant is $0.556 \mathrm{~L} \mathrm{~mol}^{-1} \mathrm{~s}^{-1}$ at some temperature. If the initial concentration of NOBr in the container is $0.25 M$, how long will it take for the concentration to decrease to $0.025 \mathrm{M}$ ?