Lucas reagent is `,`

Options

A. anhydrous `ZnCl_(2)` and conc. HCl
B. anhydrous `ZnCl_(2)` and conc. `HNO_(3)`
C. hydrous `ZnCl_(2)` and conc. `HNO_(3)`
D. hydrous `ZnCl_(2)` and conc. HCl

Answer

**Step-by-Step Solution:**

1. **Definition of Lucas Reagent**: Lukas reagent is a chemical reagent used primarily to distinguish between primary, secondary, and tertiary alcohols.

2. **Components of Lucas Reagent**: The reagent is composed of:
- Anhydrous zinc chloride (ZnCl₂)
- Concentrated hydrochloric acid (HCl)

3. **Preparation of Lucas Reagent**: To prepare Lukas reagent, anhydrous zinc chloride is mixed with concentrated hydrochloric acid. The zinc chloride acts as a Lewis acid, facilitating the reaction with alcohols.

4. **Application of Lucas Reagent**: When alcohols are treated with Lukas reagent, the reaction rate varies:
- Tertiary alcohols react immediately, forming an alkyl chloride.
- Secondary alcohols react within a few minutes.
- Primary alcohols react very slowly or not at all under these conditions.

5. **Conclusion**: Therefore, Lukas reagent is a mixture of anhydrous zinc chloride and concentrated hydrochloric acid, used to differentiate between types of alcohols based on their reactivity.

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