Which is/are the correct method for separating a mixture of benzoic acid, p-methylanline & phenol.

Options

A. `overset(aq.NaHCO_3)tooverset(aq.NaOH)to`
B. `overset(aq.HCl)tooverset(aq.NaHCO_3)to`
C. `overset(aq.NaOH)tooverset(aq.NaHCO_3)to`
D. `overset(aq.NaOH)tooverset(aq.HCl)to`

Explanation

To separate a mixture of benzoic acid, p-methylaniline, and phenol, we can use the following methods:

### Step-by-Step Solution:

1. **Identify the Compounds:**
- Benzoic Acid (C6H5COOH)
- p-Methylaniline (C6H4(CH3)NH2)
- Phenol (C6H5OH)

2. **First Method: Treat with Aqueous NaHCO3:**
- Benzoic acid is a stronger acid compared to phenol and p-methylaniline. When treated with NaHCO3, benzoic acid will react to form sodium benzoate (C6H5COONa), which is soluble in water.
- **Reaction:**
\[ \text{C6H5COOH} + \text{NaHCO3} \rightarrow \text{C6H5COONa} + \text{H2O} + \text{CO2} \]
- Phenol does not react with NaHCO3 as it is a weak acid, so it remains insoluble.
- p-Methylaniline also remains insoluble in this step.
- **Result:** Benzoic acid dissolves, while p-methylaniline and phenol remain as precipitate.

3. **Second Step: Treat with HCl:**
- Next, we can treat the remaining mixture (p-methylaniline and phenol) with HCl.
- p-Methylaniline, being a base, will react with HCl to form p-methylanilinium chloride (C6H4(CH3)NH3Cl), which is soluble in water.
- **Reaction:**
\[ \text{C6H4(CH3)NH2} + \text{HCl} \rightarrow \text{C6H4(CH3)NH3Cl} \]
- Phenol remains insoluble in HCl.
- **Result:** p-Methylaniline dissolves, while phenol remains as precipitate.

4. **Final Step: Treat with NaOH:**
- If we were to treat the mixture with NaOH first, both benzoic acid and phenol would react due to their acidic nature, leading to both being soluble.
- This would not allow for separation since both would be in solution.

5. **Conclusion:**
- The correct methods for separating the mixture are:
- **Method 1:** Treat with aqueous NaHCO3 followed by HCl.
- **Method 2:** Treat with HCl followed by NaHCO3.
- **Incorrect Method:** Treating with NaOH first would not allow for separation.

### Final Answer:
The correct methods for separating the mixture of benzoic acid, p-methylaniline, and phenol are **Method 1 and Method 2**.

---