Acid catalyzed hydration of alkenes except ethene leads to the formation of

Options

A. secondary or tertiary alcohol
B. primary alcohol
C. mixture of secondary and tertiary alcohols
D. mixture of primary and secondary alcohols

Answer

To solve the question regarding the acid-catalyzed hydration of alkenes (excluding ethene), we will follow these steps:

### Step-by-Step Solution:

1. **Understanding Acid-Catalyzed Hydration**:
- Acid-catalyzed hydration involves the addition of water (H2O) to an alkene in the presence of an acid (commonly sulfuric acid, H2SO4). This process leads to the formation of alcohols.

2. **Formation of Hydronium Ion**:
- The acid dissociates to produce hydronium ions (H3O+). This ion acts as an electrophile that will attack the alkene.

3. **Electrophilic Attack**:
- The double bond in the alkene acts as a nucleophile and attacks the hydronium ion. This results in the formation of a carbocation intermediate.
- For example, in the case of propene (CH3-CH=CH2), the double bond attacks the H+ from H3O+, leading to the formation of a secondary carbocation (CH3-CH+-CH3).

4. **Nucleophilic Attack by Water**:
- Water (H2O) then acts as a nucleophile and attacks the positively charged carbon of the carbocation. This step leads to the formation of a protonated alcohol.

5. **Deprotonation**:
- The protonated alcohol loses a proton (H+) to yield the final alcohol product.
- In the case of propene, this results in the formation of isopropanol (2-propanol), which is a secondary alcohol.

6. **Generalization for Other Alkenes**:
- For alkenes other than ethene, such as isobutylene (2-methylpropene), the same mechanism applies, leading to the formation of tertiary alcohols.
- The result is that acid-catalyzed hydration of alkenes (except ethene) typically yields secondary or tertiary alcohols.

### Conclusion:
- The acid-catalyzed hydration of alkenes (except ethene) leads to the formation of secondary or tertiary alcohols.