Among the following compounds which will be steam volatile:

Options

A. Phenol
B. p-nitrophenol
C. o-nitrophenol
D. m-nitropheneol

Explanation

To determine which of the given compounds is steam volatile, we need to analyze their structures and the type of bonding present in each compound. Steam volatile compounds can be purified through steam distillation, which typically applies to compounds with lower boiling points than water (100°C).

### Step-by-Step Solution:

1. **Understanding Steam Volatility**:
- Steam volatile compounds have boiling points lower than that of water (100°C). They can be separated from mixtures using steam distillation.

2. **Analyzing the Given Compounds**:
- The compounds mentioned are phenol, para-nitrophenol, meta-nitrophenol, and ortho-nitrophenol.

3. **Identifying Intermolecular and Intramolecular Hydrogen Bonding**:
- **Phenol**: Contains an -OH group and can form intermolecular hydrogen bonds, which increases its boiling point.
- **Para-nitrophenol**: Also has an -OH group and can form intermolecular hydrogen bonds, resulting in a higher boiling point.
- **Meta-nitrophenol**: Similar to para-nitrophenol, it can form intermolecular hydrogen bonds, leading to a higher boiling point.
- **Ortho-nitrophenol**: This compound can form intramolecular hydrogen bonds due to the proximity of the -OH and -NO2 groups. This reduces its boiling point compared to the others.

4. **Comparing Boiling Points**:
- Due to the presence of intermolecular hydrogen bonding in phenol, para-nitrophenol, and meta-nitrophenol, their boiling points are higher than that of water.
- Ortho-nitrophenol, with its intramolecular hydrogen bonding, has a lower boiling point, making it steam volatile.

5. **Conclusion**:
- Among the given compounds, **ortho-nitrophenol** is steam volatile because it has a lower boiling point due to intramolecular hydrogen bonding.

### Final Answer:
- The steam volatile compound among the options is **ortho-nitrophenol**.