Order of boiling point among primary , secondary and tertiary alcohols is :

Options

A. `3 ^(@) gt 2^(@) gt 1^(@)`
B. `1 ^(@) gt 2^(@) gt 3^(@)`
C. `3 ^(@) lt 2^(@) gt 1^(@)`
D. None of these

Answer

To determine the order of boiling points among primary, secondary, and tertiary alcohols, we need to consider the factors that influence boiling points, particularly hydrogen bonding and the steric hindrance caused by alkyl groups.

### Step-by-Step Solution:

1. **Understanding Alcohol Types**:
- **Primary Alcohol**: An alcohol where the hydroxyl group (-OH) is attached to a carbon that is connected to only one other carbon (or none). Example: Ethanol (C2H5OH).
- **Secondary Alcohol**: An alcohol where the hydroxyl group is attached to a carbon that is connected to two other carbons. Example: Isopropanol (C3H8O).
- **Tertiary Alcohol**: An alcohol where the hydroxyl group is attached to a carbon that is connected to three other carbons. Example: Tert-butanol (C4H10O).

2. **Role of Hydrogen Bonding**:
- The boiling point of alcohols is significantly influenced by hydrogen bonding between the -OH groups of different molecules. The more hydrogen bonds that can form, the higher the boiling point.

3. **Steric Hindrance**:
- In primary alcohols, the -OH group is less hindered due to fewer alkyl groups surrounding it, allowing for better exposure and more hydrogen bonding.
- In secondary alcohols, there are two alkyl groups, which create some steric hindrance, reducing the exposure of the -OH group compared to primary alcohols.
- In tertiary alcohols, the presence of three alkyl groups creates significant steric hindrance, making the -OH group less accessible for hydrogen bonding.

4. **Comparing Boiling Points**:
- **Primary Alcohols**: Highest boiling point due to minimal steric hindrance and maximum hydrogen bonding.
- **Secondary Alcohols**: Intermediate boiling point due to moderate steric hindrance and hydrogen bonding.
- **Tertiary Alcohols**: Lowest boiling point due to maximum steric hindrance and minimal hydrogen bonding.

5. **Conclusion**:
- The order of boiling points among primary, secondary, and tertiary alcohols is:
**Primary > Secondary > Tertiary**.

### Final Answer:
The order of boiling points among primary, secondary, and tertiary alcohols is: **Primary > Secondary > Tertiary**.