The fertilizer which makes the soil acidic :

Options

A. `(NH_(4))_(2)SO_(4)`
B. Super phosphate of lime
C. `CH_(3)COONa`
D. `Ca(NO_(3))_(2)`

Answer

To determine which fertilizer makes the soil acidic, we need to analyze the given options based on their chemical composition and the nature of the acids and bases they are derived from.

### Step-by-Step Solution:

1. **Understanding Soil Acidity**:
- Soil is considered acidic when its pH is less than 7. This typically occurs when the soil contains acidic salts, which are formed from the reaction of a weak base with a strong acid.

2. **Analyzing the Options**:
- **Option 1: Ammonium Sulfate (NH4)2SO4**:
- Ammonium sulfate is formed from ammonia (a weak base) and sulfuric acid (a strong acid).
- The resulting salt is acidic because it is derived from a weak base and a strong acid, resulting in a pH less than 7.

- **Option 2: Superphosphate of Lime (CaH2PO4)2**:
- This fertilizer is formed from rock phosphate and sulfuric acid.
- It is also an acidic salt, but its pH is around 6, which is less acidic than ammonium sulfate.

- **Option 3: Sodium Acetate (CH3COONa)**:
- Sodium acetate is formed from sodium hydroxide (a strong base) and acetic acid (a weak acid).
- The resulting salt is basic, with a pH greater than 7.

- **Option 4: Calcium Nitrate (Ca(NO3)2)**:
- Calcium nitrate is formed from calcium carbonate (a strong base) and nitric acid (a strong acid).
- This results in a neutral salt with a pH of 7.

3. **Conclusion**:
- Among the options, ammonium sulfate (NH4)2SO4 is the fertilizer that makes the soil acidic due to its formation from a weak base and a strong acid.

### Final Answer:
The fertilizer which makes the soil acidic is **Ammonium Sulfate (NH4)2SO4**.

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