Out of following the compound whose water solution has the highest `pH` is

Options

A. `NaCI`
B. `Na_(2)CO_(3)`
C. `NH_(4)CI`
D. `NaHCO_(3)`

Explanation

To determine which compound has the highest pH in water solution, we need to analyze the nature of each compound provided. The pH of a solution depends on whether the compound is derived from a strong acid and strong base (neutral, pH = 7), a weak acid and strong base (alkaline, pH > 7), or a strong acid and weak base (acidic, pH < 7).

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are NaCl, Na2CO3, NH4Cl, and NaHCO3.

2. **Analyze NaCl**:
- NaCl is formed from NaOH (a strong base) and HCl (a strong acid).
- Since both are strong, the solution of NaCl will have a neutral pH of 7.

3. **Analyze Na2CO3**:
- Na2CO3 is formed from NaOH (a strong base) and H2CO3 (a weak acid).
- The presence of a strong base and a weak acid means the solution will be alkaline, resulting in a pH greater than 7.

4. **Analyze NH4Cl**:
- NH4Cl is formed from NH4OH (a weak base) and HCl (a strong acid).
- This combination results in an acidic solution, which will have a pH less than 7.

5. **Analyze NaHCO3**:
- NaHCO3 is formed from NaOH (a strong base) and H2CO3 (a weak acid).
- However, it is considered an acidic salt because it can release H+ ions in solution, leading to a pH less than 7.

6. **Compare the pH Values**:
- NaCl: pH = 7 (neutral)
- Na2CO3: pH > 7 (alkaline)
- NH4Cl: pH < 7 (acidic)
- NaHCO3: pH < 7 (acidic)

7. **Conclusion**:
- Among the compounds analyzed, Na2CO3 has the highest pH because it results from a strong base and a weak acid, making its solution alkaline.

### Final Answer:
The compound whose water solution has the highest pH is **Na2CO3**.