Question

Nitrogen can be obtained :

• A. By making ammonium nitrite and ​then warming it.​
• B. By the thermal ​decomposition ​of barium azide.
• C. From liquified air by fractional distillation​.
• D. All of the above

Answer 1

The correct option is D All of the above

Industrially, dinitrogen can be obtained from liquified air by fractional distillation​. Liquid dinitrogen ​(B.P. - 77.2 K​) distils out first, leaving behind liquid oxygen​ (B.P. - 90 K​).

In the laboratory, dinitrogen can be obtained by making ammonium nitrite and ​then warming it.​
$N{H}_{4}Cl\left(aq\right)+NaN{O}_2\left(aq\right)\to N{H}_{4}N{O}_2\left(aq\right)+NaCl\left(aq\right)$
By heating ammonium nitrite ​
$N{H}_{4}N{O}_2\left(aq\right)\stackrel{\Delta }{\to }{N}_2\left(g\right)\uparrow +2H_{2}O\left(l\right)$

Very pure dinitrogen can be obtained By the thermal ​decomposition ​of barium azide and sodium azide.
$Ba\left(N_3{)}_2\right(s\left)\stackrel{\Delta }{\to }Ba\right(s)+3N_2(g)\uparrow$
$2Na{N}_3\left(s\right)\stackrel{\Delta }{\to }2Na\left(s\right)+3N_2\left(g\right)\uparrow$
$\therefore$ (d) is correct.