How many of the following compounds will liberate `NH_(3)` on heating?
`(NH_(4))_(2)SO_(4),(NH_(4))_(2)CO_(3),NH_(4)Cl,NH_(4)NO_(3),(NH_(4))_(2)Cr_(2)O_(7)`

Explanation

To determine how many of the given compounds will liberate ammonia gas (NH₃) upon heating, we will analyze each compound one by one and write the balanced equations for their thermal decomposition.

### Step 1: Analyze Ammonium Sulfate \((NH₄)₂SO₄\)

When ammonium sulfate is heated, it decomposes as follows:

\[ (NH₄)₂SO₄ \rightarrow 2 NH₃ + H₂SO₄ \]

**Conclusion**: Ammonium sulfate liberates ammonia gas.

### Step 2: Analyze Ammonium Carbonate \((NH₄)₂CO₃\)

When ammonium carbonate is heated, it decomposes as follows:

\[ (NH₄)₂CO₃ \rightarrow 2 NH₃ + H₂O + CO₂ \]

**Conclusion**: Ammonium carbonate liberates ammonia gas.

### Step 3: Analyze Ammonium Chloride \(NH₄Cl\)

When ammonium chloride is heated, it decomposes as follows:

\[ NH₄Cl \rightarrow NH₃ + HCl \]

**Conclusion**: Ammonium chloride liberates ammonia gas.

### Step 4: Analyze Ammonium Nitrate \(NH₄NO₃\)

When ammonium nitrate is heated, it decomposes as follows:

\[ NH₄NO₃ \rightarrow N₂O + 2 H₂O \]

**Conclusion**: Ammonium nitrate does not liberate ammonia gas.

### Step 5: Analyze Ammonium Dichromate \((NH₄)₂Cr₂O₇\)

When ammonium dichromate is heated, it decomposes as follows:

\[ (NH₄)₂Cr₂O₇ \rightarrow N₂ + Cr₂O₃ + 4 H₂O \]

**Conclusion**: Ammonium dichromate does not liberate ammonia gas.

### Final Count of Compounds that Liberate Ammonia

From the analysis above, the compounds that liberate ammonia gas upon heating are:

1. Ammonium sulfate \((NH₄)₂SO₄\)
2. Ammonium carbonate \((NH₄)₂CO₃\)
3. Ammonium chloride \(NH₄Cl\)

Thus, **3 compounds** will liberate ammonia gas upon heating.

### Summary of Results
- Ammonium sulfate: Yes
- Ammonium carbonate: Yes
- Ammonium chloride: Yes
- Ammonium nitrate: No
- Ammonium dichromate: No

**Total Compounds Liberating NH₃**: 3

---