In how many of the following reactions `N_(2)` gas may be released
`{:((a) NH_(4)NO_(2) overset(Delta)rarr,(b) (NH_(4))_(2) Cr_(2)O_(7) overset(Delta)rarr,(c) NH_(2)CONH_(2) + HNO_(2) overset(Delta)rarr),((d) NH_(2)CONH_(2) + NaOBr rarr,(e) NH_(3) + Cl_(2) (LR) rarr,(f) NH_(3) + Br_(2) (LR) rarr),((g) NH_(3) + NaOCl rarr,(h) NH_(3) + CaOCl_(2) rarr,(i) Ba(N_(3))_(2) overset(Delta) rarr):}`

Answer

To determine how many of the given reactions release nitrogen gas (N₂), we will analyze each reaction step by step.

### Step-by-Step Solution:

1. **Reaction (a): NH₄NO₂ →**
- Ammonium nitrite (NH₄NO₂) decomposes upon heating to produce nitrogen gas (N₂) and water (H₂O).
- **Conclusion**: Nitrogen gas is released.

2. **Reaction (b): (NH₄)₂Cr₂O₇ →**
- Ammonium dichromate ((NH₄)₂Cr₂O₇) decomposes upon heating to form chromium(III) oxide (Cr₂O₃), water (H₂O), and nitrogen gas (N₂).
- **Conclusion**: Nitrogen gas is released.

3. **Reaction (c): NH₂CONH₂ + HNO₂ →**
- Urea (NH₂CONH₂) reacts with nitrous acid (HNO₂) to produce carbon dioxide (CO₂), nitrogen gas (N₂), and water (H₂O).
- **Conclusion**: Nitrogen gas is released.

4. **Reaction (d): NH₂CONH₂ + NaOBr →**
- Urea (NH₂CONH₂) reacts with sodium hypobromite (NaOBr) to produce sodium bromide (NaBr), carbon dioxide (CO₂), and nitrogen gas (N₂).
- **Conclusion**: Nitrogen gas is released.

5. **Reaction (e): NH₃ + Cl₂ (LR) →**
- Ammonia (NH₃) reacts with chlorine (Cl₂) to produce ammonium chloride (NH₄Cl) and nitrogen gas (N₂).
- **Conclusion**: Nitrogen gas is released.

6. **Reaction (f): NH₃ + Br₂ (LR) →**
- Ammonia (NH₃) reacts with bromine (Br₂) to produce ammonium bromide (NH₄Br) and nitrogen gas (N₂).
- **Conclusion**: Nitrogen gas is released.

7. **Reaction (g): NH₃ + NaOCl →**
- Ammonia (NH₃) reacts with sodium hypochlorite (NaOCl) to produce hydrazine (NH₂NH₂), sodium chloride (NaCl), and water (H₂O).
- **Conclusion**: Nitrogen gas is not released.

8. **Reaction (h): NH₃ + Ca(OCl)₂ →**
- Ammonia (NH₃) reacts with calcium oxychloride (Ca(OCl)₂) to produce calcium chloride (CaCl₂), water (H₂O), and nitrogen gas (N₂).
- **Conclusion**: Nitrogen gas is released.

9. **Reaction (i): Ba(N₃)₂ →**
- Barium azide (Ba(N₃)₂) decomposes upon heating to produce barium (Ba) and nitrogen gas (N₂).
- **Conclusion**: Nitrogen gas is released.

### Summary of Results:
- Nitrogen gas is released in reactions: (a), (b), (c), (d), (e), (f), (h), and (i).
- **Total reactions releasing nitrogen gas**: 8

### Final Answer:
**Nitrogen gas is released in 8 reactions.**