Question

How many electrons are needed to reduce N$_2$ to NH$_3$?

• A. 3
• B. 4
• C. 5
• D. 6

Hint:

Reduction tip: \begin{itemize} \item Change in oxidation state $\times$ number of atoms = electrons transferred \item N$_2$ $\rightarrow$ NH$_3$ requires 6 electrons \end{itemize}

Answer 1

The Correct Option is D

Concept: Reduction of nitrogen to ammonia occurs in Haber process or biological nitrogen fixation. Balanced half-reaction: \[ \text{N}_2 + 6e^- + 6H^+ \rightarrow 2\text{NH}_3 \] Step 1: Oxidation states In N$_2$: \[ \text{N oxidation state} = 0 \] In NH$_3$: \[ \text{N oxidation state} = -3 \] Each nitrogen gains 3 electrons. Step 2: Total electrons Two nitrogen atoms: \[ 3 \times 2 = 6 \text{ electrons} \] Conclusion: 6 electrons required to reduce N$_2$ to NH$_3$.