The Hinsberg's method is used for :

Options

A. preparation of primary amines
B. preparation of secondary amines
C. preparation of tertiary amines
D. separation of amine mixtures

Answer

To solve the question regarding the Hinsberg's method, we will analyze the options provided and understand the purpose of the Hinsberg's reagent in organic chemistry.

### Step-by-Step Solution:

1. **Understanding Hinsberg's Reagent**:
- Hinsberg's reagent is benzenesulfonyl chloride (C6H5SO2Cl). It is used to differentiate between primary, secondary, and tertiary amines.

2. **Reaction with Primary Amines**:
- When a primary amine reacts with Hinsberg's reagent, it forms a sulfonamide that is soluble in alkaline solutions. This is due to the presence of an acidic hydrogen in the sulfonamide product.

3. **Reaction with Secondary Amines**:
- A secondary amine also reacts with Hinsberg's reagent to form a sulfonamide, but this product is insoluble in alkaline solutions. This is because secondary amines do not have an acidic hydrogen that can be released.

4. **Reaction with Tertiary Amines**:
- Tertiary amines do not react with Hinsberg's reagent at all. Therefore, no sulfonamide product is formed.

5. **Conclusion on the Purpose of Hinsberg's Method**:
- The Hinsberg's method is primarily used for the separation and identification of amine mixtures by differentiating between primary, secondary, and tertiary amines based on their solubility in alkali and their reactivity with the reagent.

6. **Final Answer**:
- The correct answer to the question "The Hinsberg's method is used for:" is **separation of amine mixture** (Option D).