Which salt cannot be cannot be hydrolysed ?

Options

A. Potassium nitrate
B. Potassium cyanide
C. Potassium succinate
D. Potassium carbonate

Answer

To determine which salt cannot be hydrolyzed, we need to understand the concept of hydrolysis in relation to the nature of the salts formed from strong acids and strong bases, weak acids, and weak bases.

### Step-by-step Solution:

1. **Understanding Hydrolysis**: Hydrolysis is a reaction between a salt and water, where the salt dissociates into its constituent ions. The nature of these ions (whether they come from strong or weak acids/bases) determines if hydrolysis occurs.

2. **Identifying Salt Composition**: We need to analyze the given salts and identify whether they are formed from strong acids and strong bases or from weak acids/bases.

3. **Analyzing the Options**:
- **Option 1: Potassium Nitrate (KNO3)**:
- Formed from KOH (strong base) and HNO3 (strong acid).
- Since both the acid and base are strong, KNO3 is neutral and will not undergo hydrolysis.

- **Option 2: Potassium Cyanide (KCN)**:
- Formed from KOH (strong base) and HCN (weak acid).
- This salt can undergo hydrolysis because HCN is a weak acid.

- **Option 3: Potassium Succinate**:
- Formed from KOH (strong base) and succinic acid (weak acid).
- This salt can also undergo hydrolysis because succinic acid is weak.

- **Option 4: Potassium Carbonate (K2CO3)**:
- Formed from KOH (strong base) and carbonic acid (weak acid).
- This salt can undergo hydrolysis as well because carbonic acid is weak.

4. **Conclusion**: The only salt that cannot be hydrolyzed is **Potassium Nitrate (KNO3)**, as it is formed from a strong acid and a strong base, resulting in a neutral salt.

### Final Answer:
**Potassium Nitrate (KNO3)** cannot be hydrolyzed.

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