How many are basic ?

Explanation

To determine how many of the given compounds are basic, we will analyze each compound one by one based on their nature (acidic, basic, or neutral).

### Step-by-Step Solution:

1. **Analyze NH4Cl**:
- NH4Cl is formed from the reaction of a strong acid (HCl) and a weak base (NH4OH).
- Since it is a salt of a weak base and a strong acid, it will undergo hydrolysis and produce an acidic solution.
- **Conclusion**: NH4Cl is not basic.

2. **Analyze NaOH**:
- NaOH is a strong base.
- **Conclusion**: NaOH is basic.

3. **Analyze Acetic Acid (CH3COOH)**:
- Acetic acid is a weak acid.
- **Conclusion**: Acetic acid is not basic.

4. **Analyze NaCl**:
- NaCl is formed from the reaction of a strong acid (HCl) and a strong base (NaOH).
- Since both the acid and base are strong, NaCl is a neutral salt and does not undergo hydrolysis.
- **Conclusion**: NaCl is not basic.

5. **Analyze NH3 + NH4Cl**:
- This is a buffer solution consisting of a weak base (NH3) and its corresponding salt (NH4Cl).
- The presence of NH3 makes this solution basic.
- **Conclusion**: NH3 + NH4Cl is basic.

6. **Analyze HClO4**:
- HClO4 (perchloric acid) is a strong acid.
- **Conclusion**: HClO4 is not basic.

7. **Analyze Ammonium Sulfate ((NH4)2SO4)**:
- Ammonium sulfate is formed from a weak base (NH4OH) and a strong acid (H2SO4).
- It will undergo hydrolysis and produce an acidic solution.
- **Conclusion**: Ammonium sulfate is not basic.

8. **Analyze Potassium Sulfate (K2SO4)**:
- K2SO4 is formed from a strong acid (H2SO4) and a strong base (KOH).
- Since both components are strong, K2SO4 is a neutral salt and does not undergo hydrolysis.
- **Conclusion**: K2SO4 is not basic.

### Summary of Basic Compounds:
- The basic compounds identified are:
- NaOH
- NH3 + NH4Cl

Therefore, the total number of basic compounds is **2**.

### Final Answer:
**2 basic compounds.**

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