In which of the following reactions `NH_(3)` gas evolution occurs?

Options

A. `NO_(3)^(-)+Zn+dil.H_(2)SO_(4) overset(warm)to`
B. `NH_(4)^(+)"salt"+NaOH overset(Delta)to`
C. `AlN+"steam"to`
D. `CH_(3)COONH_(3)overset(Delta)to`

Explanation

To determine in which of the given reactions ammonia (NH₃) gas evolution occurs, we will analyze each option step by step.

### Step 1: Analyze Option 1
**Reaction:** Zn + Dilute H₂SO₄ (warm)

In this reaction, zinc (Zn) reacts with dilute sulfuric acid (H₂SO₄). The expected products are zinc sulfate and hydrogen gas. Although ammonia is not directly produced in this reaction, it can be formed under specific conditions involving nitrogen oxides. However, in the context of this reaction, NH₃ is not evolved.

**Conclusion for Option 1:** No NH₃ gas is evolved.

### Step 2: Analyze Option 2
**Reaction:** NH₄ salt + NaOH (heated)

When an ammonium salt reacts with sodium hydroxide (NaOH) upon heating, ammonia gas is released. The reaction can be represented as:
\[ \text{NH}_4\text{Cl} + \text{NaOH} \rightarrow \text{NH}_3 + \text{NaCl} + \text{H}_2\text{O} \]

**Conclusion for Option 2:** NH₃ gas is evolved.

### Step 3: Analyze Option 3
**Reaction:** AlN + H₂O (steam)

Aluminum nitride (AlN) reacts with steam (water) to produce aluminum oxide and ammonia gas:
\[ \text{AlN} + 3\text{H}_2\text{O} \rightarrow \text{Al}_2\text{O}_3 + 2\text{NH}_3 \]

**Conclusion for Option 3:** NH₃ gas is evolved.

### Step 4: Analyze Option 4
**Reaction:** CH₃COONH₄ (heated)

When ammonium acetate (CH₃COONH₄) is heated, it decomposes to form acetic acid and ammonia:
\[ \text{CH}_3\text{COONH}_4 \rightarrow \text{CH}_3\text{COOH} + \text{NH}_3 \]

**Conclusion for Option 4:** NH₃ gas is evolved.

### Final Conclusion
Based on the analysis:
- **Option 1:** No NH₃ gas evolved.
- **Option 2:** NH₃ gas evolved.
- **Option 3:** NH₃ gas evolved.
- **Option 4:** NH₃ gas evolved.

Thus, the reactions that evolve NH₃ gas are **Option 2, Option 3, and Option 4**.

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