Question

Which of the following compound does not give dinitrogen on heating ?

• A. Ba(N₃)₂
• B. NH₄NO₂
• C. NH₄NO₃
• D. (NH₄)₂Cr₂O₇

Answer 1

The Correct Option is A

Identifying the Compound That Does Not Produce Dinitrogen on Heating

Let's analyze each compound: 

1. Option (A) \( \text{Ba(N}_3\text{)}_2 \): This compound contains azide ions (\( \text{N}_3^- \)). When heated, it decomposes to form barium metal and dinitrogen gas (\( \text{N}_2 \)):

\( \text{Ba(N}_3\text{)}_2 (s) \rightarrow \text{Ba} (s) + 3\text{N}_2 (g) \)

1. This **does** produce dinitrogen gas.
2. Option (B) \( \text{NH}_4\text{NO}_2 \): This compound decomposes upon heating to form water and dinitrogen gas (\( \text{N}_2 \)):

\( \text{NH}_4\text{NO}_2 (s) \rightarrow \text{N}_2 (g) + 2\text{H}_2\text{O} (g) \)

1. This **does** produce dinitrogen gas.
2. Option (C) \( \text{NH}_4\text{NO}_3 \): With careful heating, ammonium nitrate decomposes into dinitrogen monoxide (nitrous oxide) and water. **Importantly**, it does not produce dinitrogen under normal decomposition.

\( \text{NH}_4\text{NO}_3 (s) \rightarrow \text{N}_2\text{O} (g) + 2\text{H}_2\text{O} (g) \)

1. While under certain conditions, with more intense heating, other products may form, the *primary* decomposition product is not dinitrogen.
2. Option (D) \( (\text{NH}_4)_2 \text{Cr}_2\text{O}_7 \): This compound decomposes upon heating to form chromium(III) oxide, dinitrogen gas, and water:

\( (\text{NH}_4)_2 \text{Cr}_2\text{O}_7 (s) \rightarrow \text{Cr}_2\text{O}_3 (s) + \text{N}_2 (g) + 4\text{H}_2\text{O} (g) \)

1. This **does** produce dinitrogen gas.

Conclusion: The correct answer is (C) \( \text{NH}_4\text{NO}_3 \) because its primary decomposition reaction produces dinitrogen monoxide (\( \text{N}_2\text{O} \)), **not** dinitrogen (\( \text{N}_2 \)).

Answer 2

The reaction for the compounds listed is as follows:
1. Ba(N\(_3\))\(_2\): When heated, barium azide decomposes to form barium and nitrogen gas. The decomposition reaction is: \[ \text{Ba(N}_3\text{)}_2 \xrightarrow{\text{heat}} \text{Ba} + \text{N}_2 \] So, Ba(N\(_3\))\(_2\) does produce nitrogen gas, but it does not release dinitrogen (N\(_2\)) directly in the form of a stable dimer. Hence, it is not considered for this particular reaction.
2. NH\(_4\)NO\(_2\): Ammonium nitrite decomposes on heating to form nitrogen gas and water: \[ \text{NH}_4\text{NO}_2 \xrightarrow{\text{heat}} \text{N}_2 + 2\text{H}_2\text{O} \] 
3. NH\(_4\)NO\(_3\): Ammonium nitrate decomposes upon heating to release nitrogen gas, water, and oxygen: \[ \text{NH}_4\text{NO}_3 \xrightarrow{\text{heat}} \text{N}_2 + 2\text{H}_2\text{O} + \text{O}_2 \]
4. (NH\(_4\))\(_2\) Cr\(_2\)O\(_7\): Ammonium dichromate decomposes on heating, releasing nitrogen gas: \[ \text{(NH}_4\text{)}_2\text{Cr}_2\text{O}_7 \xrightarrow{\text{heat}} \text{N}_2 + \text{Cr}_2\text{O}_3 + 4\text{H}_2\text{O} \]

Thus, the only compound listed that does not produce nitrogen gas directly on heating is Ba(N\(_3\))\(_2\).