Question

For a reaction, \( NH_{4}NO_{2} \rightarrow N_{2} + 2H_{2}O \). Which from following phenomena is true regarding nitrogen?

• A. Oxidised
• B. Reduced
• C. Oxidised as well as reduced
• D. Neither oxidised nor reduced

Hint:

This is a comproportionation reaction where different oxidation states of the same element combine to form a single product.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
This question asks for the oxidation state changes of nitrogen atoms in the thermal decomposition of ammonium nitrite.
Step 2: Detailed Explanation:
The compound \( NH_{4}NO_{2} \) consists of two different ions: the ammonium ion (\( NH_{4}^{+} \)) and the nitrite ion (\( NO_{2}^{-} \)).
1. Oxidation state of N in \( NH_{4}^{+} \):
\( x + 4(+1) = +1 \Rightarrow x = -3 \).
2. Oxidation state of N in \( NO_{2}^{-} \):
\( y + 2(-2) = -1 \Rightarrow y = +3 \).
In the product \( N_{2} \), the oxidation state of N is 0.
Changes:
- Nitrogen from \( NH_{4}^{+} \) goes from -3 to 0 (loss of electrons, oxidation).
- Nitrogen from \( NO_{2}^{-} \) goes from +3 to 0 (gain of electrons, reduction).
Since one nitrogen atom is oxidized and the other is reduced, nitrogen is both oxidized and reduced in this reaction (Comproportionation).
Step 3: Final Answer:
Nitrogen is oxidised as well as reduced.