Chemical Kinetics

The reaction given below $2 \mathrm{NH}_{3(\mathrm{g})} \xrightarrow{\mathrm{Pt}} \mathrm{N}_{2(\mathrm{g})}+3 \mathrm{H}_{2(\mathrm{g})}$ has rate of reaction $2.5 \times 10^{-6} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{sec}^{-1}$ formation of $\mathrm{H}_{2(\mathrm{~g})}$ ?