The product formed during Hell-Volhard-Zelinsky reaction is

Options

A. `R-underset(X)underset(|)CH-COOH`
B. `R-CH_(2)-COX`
C. `R-underset(X)underset(|)overset(X)overset(|)C-COOH`
D. `R-underset(X)underset(|)CH-CH_(2)-COOH`

Explanation

To determine the product formed during the Hell-Volhard-Zelinsky reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Reaction**: The Hell-Volhard-Zelinsky reaction involves the halogenation of carboxylic acids that have at least one alpha-hydrogen. This reaction typically uses chlorine or bromine in the presence of red phosphorus.

2. **Identifying the Reactants**: The reactants in this reaction are carboxylic acids that contain an alpha-hydrogen. The general structure of a carboxylic acid is R-COOH, where R is a hydrocarbon chain.

3. **Mechanism of the Reaction**:
- The alpha-hydrogen (the hydrogen atom on the carbon adjacent to the carboxyl group) is replaced by a halogen atom (Cl or Br).
- This halogenation occurs through the formation of an acyl halide intermediate, followed by the substitution of the alpha-hydrogen.

4. **Formation of the Product**: The product of the Hell-Volhard-Zelinsky reaction is an alpha-halo-carboxylic acid. This means that the resulting compound will have a halogen atom (X) at the alpha position of the carboxylic acid.

5. **Conclusion**: Therefore, the product formed during the Hell-Volhard-Zelinsky reaction is an alpha-halo-carboxylic acid, specifically represented as R-COX, where X is the halogen (Cl or Br).

### Final Answer:
The product formed during the Hell-Volhard-Zelinsky reaction is **alpha-halo-carboxylic acid**.

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