When phenol is treated with `D_(2)SO_(4)//D_(2)O`, some of the hydrogens get exchanged. The final product in the exchange reaction is

Options

A.
B.
C.
D.

Explanation

To solve the question regarding the exchange of hydrogens in phenol when treated with \( D_2SO_4 \) and \( D_2O \), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Reactants**:
- We have phenol (\( C_6H_5OH \)), which contains a hydroxyl group (-OH) attached to a benzene ring.
- The reactants \( D_2SO_4 \) and \( D_2O \) are deuterated forms of sulfuric acid and water, respectively. Deuterium (D) is an isotope of hydrogen.

2. **Reaction Mechanism**:
- When phenol is treated with \( D_2SO_4 \) and \( D_2O \), the hydroxyl group (-OH) can undergo exchange reactions where the hydrogen atoms can be replaced by deuterium atoms.
- The hydroxyl hydrogen (H) can be replaced by deuterium (D) from \( D_2O \).

3. **Electrophilic Substitution**:
- The -OH group in phenol is an ortho/para directing group due to its electron-donating nature. This means that any electrophilic substitution will occur at the ortho and para positions relative to the -OH group.
- In this case, the electrophile can be \( D^+ \) from the deuterated sulfuric acid.

4. **Formation of Products**:
- The reaction can lead to the formation of two types of products:
- Deuterium can be substituted at the ortho position, resulting in \( C_6H_4(OH)(D) \) (where D is at ortho).
- Deuterium can also be substituted at the para position, resulting in \( C_6H_4(OH)(D) \) (where D is at para).
- The hydrogen atom from the hydroxyl group can also be replaced by deuterium, leading to \( C_6H_5(OD) \).

5. **Final Products**:
- The final products will be a mixture of ortho and para substituted phenol derivatives, where at least one hydrogen atom has been replaced by deuterium. The hydroxyl group can also be converted to deuterated hydroxyl (-OD).
- Thus, the final products in the exchange reaction will be \( C_6H_4(OH)(D) \) at ortho and para positions and \( C_6H_5(OD) \).

### Conclusion:
The final products in the exchange reaction of phenol with \( D_2SO_4 \) and \( D_2O \) will be deuterated phenol derivatives, specifically ortho and para substituted phenols with deuterium and the deuterated hydroxyl group.

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