Sulfanillic acid at `pH = 2` and `12` exists as....and migrates towards..... Respectively.

Options

A.
B. `(II)` anode and `(I)` carhode
C. At both `pH`, only `(I)` and migrates towards the cathode
D. At both `pH`, only `(II)` and migrates towards the anode

Explanation

To solve the problem regarding the behavior of sulfanillic acid at different pH levels, we will analyze the structure of sulfanillic acid and how it interacts with the surrounding environment at pH 2 and pH 12.

### Step-by-Step Solution:

1. **Understanding the Structure of Sulfanillic Acid**:
- Sulfanillic acid has the following structure:
- An amino group (-NH2)
- A sulfonic acid group (-SO3H)
- The overall structure can be represented as:
```
NH2
|
SO3H
```

2. **Analyzing at pH 2**:
- At pH 2, the environment is acidic. This means there are excess H⁺ ions present.
- The amino group (-NH2) can accept a proton (H⁺) from the solution, becoming positively charged (-NH3⁺).
- Therefore, at pH 2, sulfanillic acid exists primarily in its cationic form:
```
NH3⁺
|
SO3H
```

3. **Migration of the Cation**:
- Cations (positively charged species) migrate towards the cathode in an electrochemical cell because the cathode is negatively charged.
- Thus, at pH 2, sulfanillic acid exists as a cation and migrates towards the cathode.

4. **Analyzing at pH 12**:
- At pH 12, the environment is basic. This means there are excess OH⁻ ions present.
- The OH⁻ ions can deprotonate the sulfonic acid group (-SO3H), leading to the formation of a negatively charged sulfonate ion (-SO3⁻).
- Therefore, at pH 12, sulfanillic acid exists primarily as an anion:
```
NH2
|
SO3⁻
```

5. **Migration of the Anion**:
- Anions (negatively charged species) migrate towards the anode in an electrochemical cell because the anode is positively charged.
- Thus, at pH 12, sulfanillic acid exists as an anion and migrates towards the anode.

### Final Answer:
- At pH 2, sulfanillic acid exists as a cation and migrates towards the cathode.
- At pH 12, sulfanillic acid exists as an anion and migrates towards the anode.

### Summary:
- **pH 2**: Cation → Migrates towards **Cathode**
- **pH 12**: Anion → Migrates towards **Anode**