How will you distinguish between 1-phenylethanol and 2-phenylethanol ?

Answer

To distinguish between 1-phenylethanol and 2-phenylethanol, we can follow these steps:

### Step 1: Understand the Structures
1. **1-Phenylethanol** (C6H5CH(OH)CH3): This compound has a hydroxyl (-OH) group attached to the first carbon of the ethyl chain.
2. **2-Phenylethanol** (C6H5CH2CH(OH)CH3): This compound has a hydroxyl (-OH) group attached to the second carbon of the ethyl chain.

### Step 2: Identify the Functional Groups
- 1-Phenylethanol has a secondary alcohol functional group (the -OH is attached to a carbon that is connected to two other carbons).
- 2-Phenylethanol has a primary alcohol functional group (the -OH is attached to a carbon that is connected to only one other carbon).

### Step 3: Perform the Iodoform Test
- The Iodoform test is a qualitative test used to identify the presence of a methyl ketone or a secondary alcohol that can be oxidized to a methyl ketone.
- For the Iodoform test, you will react the alcohol with iodine (I2) in the presence of sodium hydroxide (NaOH).

### Step 4: Analyze the Results
1. **1-Phenylethanol**: When subjected to the Iodoform test, it will give a positive result, forming a yellow precipitate of iodoform (CHI3). This is because it can be oxidized to a methyl ketone.
2. **2-Phenylethanol**: This compound will not give a positive Iodoform test, as it does not have the necessary structure to form a methyl ketone.

### Conclusion
By performing the Iodoform test, you can distinguish between 1-phenylethanol and 2-phenylethanol. The presence of a yellow precipitate indicates the presence of 1-phenylethanol, while no precipitate indicates 2-phenylethanol.

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