Which of the following will not give positive test with neutral `FeCl_(3)` ?

Options

A. Nitrophenol
B. Phenol
C. Allyl alcohol
D. o-cresol

Answer

To determine which compound will not give a positive test with neutral FeCl3, we need to understand the nature of the compounds in question and their relationship with phenolic groups.

### Step-by-Step Solution:

1. **Understanding the Test**: Neutral FeCl3 is used to test for the presence of phenolic compounds. When phenols react with FeCl3, they form a violet-brown complex due to the formation of a phenoxy iron complex.

2. **Identifying the Compounds**: The question presents four compounds. We need to analyze each compound to see if it contains a phenolic -OH group, as only those will react positively with FeCl3.

3. **Analyzing Each Compound**:
- **Compound 1: Phenol (C6H5OH)**: This compound contains a phenolic -OH group. Therefore, it will give a positive test with FeCl3, forming a violet-brown complex.
- **Compound 2: Ortho-Cresol (C6H4(CH3)OH)**: This compound also contains a phenolic -OH group (with a methyl group attached). It will also give a positive test with FeCl3.
- **Compound 3: Tri-Nitrophenol**: This compound has a phenolic -OH group as well, despite having nitro groups attached. It will still react with FeCl3 and give a positive test.
- **Compound 4: Allyl Alcohol (CH2=CH-CH2OH)**: This compound does not contain a phenolic -OH group. Therefore, it will not react with FeCl3 and will give a negative test.

4. **Conclusion**: The compound that will not give a positive test with neutral FeCl3 is Allyl Alcohol.

### Final Answer:
**Allyl Alcohol will not give a positive test with neutral FeCl3.**