pBlock ElementsII - Result Question 133
####18. Extra pure $N _2$ can be obtained by heating
(a) $NH _3$ with $CuO$
(b) $NH _4 NO _3$
(c) $\left(NH _4\right) _2 Cr _2 O _7$
(d) $Ba\left(N _3\right) _2$
(2011)
Show Answer
Solution:
- $Ba\left(N _3\right) _2 \xrightarrow{\text { Heat }} Ba(s)+3 N _2(g)$
Azide salt of barium can be obtained in purest form as well as the decomposition product contain solid $Ba$ as by product alongwith gaseous nitrogen, hence no additional step of separation is required.
Other reactions are
$$ \begin{gathered} NH _4 NO _3 \xrightarrow{\text { Heat }} N _2 O+2 H _2 O \ 2 NH _3+3 CuO \xrightarrow{\text { Heat }} 3 Cu+3 H _2 O+N _2 \ \left(NH _4\right) _2 Cr _2 O _7 \stackrel{\text { Heat }}{\longrightarrow} Cr _2 O _3+4 H _2 O+N _2 \end{gathered} $$
