A compound whose aqueous solution will have the highest `pH`

Options

A. NaCl
B. `NaHCO_(3)`
C. `Na_(2)CO_(3)`
D. `NH_(4)Cl`

Explanation

To determine which compound will have the highest pH in an aqueous solution, we can analyze the nature of each compound based on their acid-base properties. Here’s a step-by-step breakdown:

### Step 1: Identify the Compounds
We have the following compounds to analyze:
1. NaCl
2. NaHCO3
3. Na2CO3
4. NH4Cl

### Step 2: Analyze NaCl
- **Nature**: NaCl is formed from a strong acid (HCl) and a strong base (NaOH).
- **pH**: The solution of NaCl in water is neutral, resulting in a pH of approximately 7.

### Step 3: Analyze NaHCO3
- **Nature**: NaHCO3 (sodium bicarbonate) is an acidic salt derived from a weak acid (H2CO3) and a strong base (NaOH).
- **pH**: In aqueous solution, NaHCO3 can release H+ ions, leading to a pH less than 7.

### Step 4: Analyze Na2CO3
- **Nature**: Na2CO3 (sodium carbonate) is formed from a weak acid (H2CO3) and a strong base (NaOH).
- **pH**: The solution of Na2CO3 in water will be basic due to the presence of excess OH- ions from the strong base. Therefore, the pH will be greater than 7.

### Step 5: Analyze NH4Cl
- **Nature**: NH4Cl is formed from a strong acid (HCl) and a weak base (NH4OH).
- **pH**: The solution of NH4Cl will be acidic, resulting in a pH less than 7 due to the release of H+ ions.

### Step 6: Compare pH Values
- **NaCl**: pH ≈ 7 (neutral)
- **NaHCO3**: pH < 7 (acidic)
- **Na2CO3**: pH > 7 (basic)
- **NH4Cl**: pH < 7 (acidic)

### Conclusion
Among the given compounds, **Na2CO3** will have the highest pH in an aqueous solution because it is basic.

### Final Answer
The compound whose aqueous solution will have the highest pH is **Na2CO3**.

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