Which conformer of propene, ethanal (acetaldehyde), and propanaldehyde is more stable?

Explanation

To determine which conformer of propene, ethanal (acetaldehyde), and propanaldehyde is more stable, we need to analyze the conformations of each compound and the factors that contribute to their stability.

### Step 1: Analyze Propene
1. **Structure**: Propene has the formula CH₃CH=CH₂. The double bond between the second and third carbon atoms restricts rotation.
2. **Conformers**: The two main conformers are staggered and eclipsed. In the eclipsed conformation, the hydrogen atoms on adjacent carbons are aligned, which leads to increased steric strain.
3. **Stability**: However, due to the presence of dipole-dipole interactions in the eclipsed form (due to the partial positive and negative charges), this form is more stable than expected.

### Step 2: Analyze Ethanal (Acetaldehyde)
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