Which of the following alkenes is most stable?

Options

A. `(CH_(3))_(2)CH=CH_(2)`
B. `CH_(3)CH=CHCH_(3)`
C. `(CH_(3))_(2)C=C(CH_(3))_(2)`
D. `CH_(3)CH=CH_(2)`

Explanation

To determine which alkene is the most stable among the given options, we need to analyze the structures based on the number of alpha hydrogens. The stability of alkenes is directly proportional to the number of alpha hydrogens present in the molecule. Alpha hydrogens are those attached to the sp3 hybridized carbon atoms that are adjacent to the sp2 hybridized carbon atoms involved in the double bond.

### Step-by-Step Solution:

1. **Identify the Structures**:
- **Option 1**: CH3-CH=CH2 (Propene)
- **Option 2**: CH3-CH=CH-CH3 (Butene)
- **Option 3**: CH3-C(CH3)=C(CH3)-CH3 (2-Butene)
- **Option 4**: CH3-CH=CH2 (This is the same as Option 1)

2. **Draw the Structures**:
- For **Option 1**:
- Structure: CH3-CH=CH2
- Alpha Hydrogens: 6 (from the two CH3 groups)
- For **Option 2**:
- Structure: CH3-CH=CH-CH3
- Alpha Hydrogens: 6 (3 from each CH3)
- For **Option 3**:
- Structure: CH3-C(CH3)=C(CH3)-CH3
- Alpha Hydrogens: 12 (3 from each CH3, 4 CH3 groups total)
- For **Option 4**:
- Structure: CH3-CH=CH2 (same as Option 1)
- Alpha Hydrogens: 6

3. **Count the Alpha Hydrogens**:
- **Option 1**: 6 alpha hydrogens
- **Option 2**: 6 alpha hydrogens
- **Option 3**: 12 alpha hydrogens
- **Option 4**: 6 alpha hydrogens

4. **Determine Stability**:
- The stability of alkenes increases with the number of alpha hydrogens.
- **Option 3** has the highest number of alpha hydrogens (12), making it the most stable alkene among the options.

5. **Conclusion**:
- Therefore, the most stable alkene is **Option 3** (CH3-C(CH3)=C(CH3)-CH3).

### Final Answer:
**Option 3** is the most stable alkene.