On heating ammonium dichromate and barium azide separately we get:

1. N2 in both cases
2. N2 with ammonium dichromate and NO with barium azide
3. N2O with ammonium dichromate and N2 with barium azide
4. N2O with ammonium dichromate and NO2 with barium azide
 
 



Hint: Preparation of nitrogen gas

On heating ammonium dichromate and barium azide it produces N2 gas separately.

\(\begin{gathered} \left(\mathrm{NH}_{4}\right)_{2} \mathrm{Cr}_{2} \mathrm{O}_{7} \stackrel{\Delta}{\rightarrow} \mathrm{N}_{2}+4 \mathrm{H}_{2} \mathrm{O}+\mathrm{Cr}_{2} \mathrm{O}_{3} \\ \mathrm{Ba}\left(\mathrm{N}_{3}\right)_{2} \rightarrow \mathrm{Ba}+3 \mathrm{~N}_{2} \end{gathered}\)