The compound(s) which generate(s) $N_2$ gas upon thermal decomposition below ${300}^{o}C$ is (are)

• A

  $N{H}_{4}N{O}_3$
• Correct answer
  B

  ${{\left(N{H}_4\right)}_2}_{ }C{r}_2{O}_7$
• Correct answer
  C

  $Ba{\left(N_3\right)}_2$
• D

  $M{g}_3{N}_2$

Solution

$\left(A\right)$

$\left(B\right)$ ${\left(N{H}_4\right)}_{2}C{r}_2{O}_7\stackrel{∆}{\to }{N}_2+C{r}_2{O}_3+4H_{2}O$
$\left(C\right)$ $Ba{\left(N_3\right)}_2\stackrel{∆}{\to }Ba+3N_2$
$\left(D\right)$ $M{g}_3{N}_2$ (It does not decompose into N₂)

Hence, the correct answer is options: 'B', 'C'.