Question

Consider the following compounds 1. $(NH_4)_2Cr_2O_7$ 2. $NH_4NO_2$ 3. $NH_4 VO_3$ 4. $NH_4 NO_3$ Which compound(s) yield nitrogen gas upon heating?

• A. 1 and 2
• B. 2 and 3
• C. 3 and 4
• D. 1 and 4

Answer 1

Answer: (A)

1 and 2

Answer 2

The correct option is(A): 1 and 2.

Only $\left( NH _{4}\right)_{2} Cr _{2} O _{7}$ and $NH _{4} NO _{2}$ give $N _{2}$ on

heating.

(i) $\left( NH _{4}\right)_{2} Cr _{2} O _{7} \stackrel{\Delta}{\longrightarrow} Cr _{2} O _{3}+4 H _{2} O + N _{2}$

(ii) ${NH4NO2 ->[\text{Thermal decomposition}][{\Delta}] 2 H_2O +N2}$