Chemical Kinetics

For the reaction \(\mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightarrow 2 \mathrm{NH}_{3(\mathrm{~g})}\), rate of disappearance of \(\mathrm{N}_{2(\mathrm{~g})}\) is \(2.22 \times 10^{-3} \mathrm{~mol} \mathrm{~dm}^{-3}\). What is the rate of appearance of \(\mathrm{NH}_{3(\mathrm{~g})}\) ?