Which of the following is not an acidic salt?

Options

A. `CuSO_4`
B. `Na_2 CO_3`
C. `ZnSO_4`
D. `NH_4 NO_3`

Answer

To determine which of the following salts is not an acidic salt, we first need to understand what acidic salts are.

### Step-by-Step Solution:

1. **Definition of Acidic Salt**:
- An acidic salt is formed from a strong acid and a weak base.

2. **Identify the Options**:
- We need to analyze the given salts to determine if they are acidic salts or not.

3. **Examine Each Salt**:
- **Option A: CuSO4 (Copper Sulfate)**
- Formed from sulfuric acid (H2SO4 - strong acid) and copper hydroxide (Cu(OH)2 - weak base).
- Conclusion: CuSO4 is an acidic salt.

- **Option B: Na2CO3 (Sodium Carbonate)**
- Formed from carbonic acid (H2CO3 - weak acid) and sodium hydroxide (NaOH - strong base).
- Conclusion: Na2CO3 is a basic salt, not an acidic salt.

- **Option C: ZnSO4 (Zinc Sulfate)**
- Formed from sulfuric acid (H2SO4 - strong acid) and zinc hydroxide (Zn(OH)2 - weak base).
- Conclusion: ZnSO4 is an acidic salt.

- **Option D: NH4NO3 (Ammonium Nitrate)**
- Formed from nitric acid (HNO3 - strong acid) and ammonium hydroxide (NH4OH - weak base).
- Conclusion: NH4NO3 is an acidic salt.

4. **Final Conclusion**:
- The only salt that is not an acidic salt among the options is **Na2CO3** (Sodium Carbonate).

### Answer:
**Na2CO3 is not an acidic salt.**