$\mathrm{Ba}\left(\mathrm{N}_3\right)_2 \stackrel{\text { Heat }}{\longrightarrow} \mathrm{Ba}(\mathrm{s})+3 \mathrm{~N}_2(\mathrm{~g})$
Azide salt of barium can be obtained in purest form as well as the decomposition product contain solid $\mathrm{Ba}$ as byproduct along with gaseous nitrogen, hence no additional step of separation is required.
Other reactions are:
