Conformational Analysis
Mediumchemistry
Most stable conformation of n-butane is:
Select the correct option:
Solution
Incorrect! Answer:
Anti staggered (methyls 180° apart)
- Types of Strain:
- Torsional Strain: Repulsion between electron clouds of eclipsed bonds.
- Steric Strain: Physical crowding of bulky groups (e.g., methyl masses).
- Conformations of Butane:
- Eclipsed (0∘): Maximum strain (highest energy).
- Gauche (60∘): Staggered but methyl groups are close, causing some steric strain.
- Anti (180∘): Staggered and large methyl groups are as far apart as possible.
- Stability: The Anti-conformation maximizes distances between bulky methyl groups, minimizing both torsional and steric strain.
- Result: It is the global energy minimum (most stable).
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
About This Question
- Subject
- chemistry
- Chapter
- hydrocarbons
- Topic
- conformational analysis
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
Anti staggered (methyls 180° apart)
- Types of Strain:
- Torsional Strain: Repulsion between electron clouds of eclipsed bonds.
- Steric Strain: Physical crowding of bulky groups (e.g., methyl masses).
- Conformations of Butane:
- Eclipsed (0∘): Maximum strain (highest energy).
- Gauche (60∘): Staggered but methyl groups are close, causing some steric strain.
- Anti (180∘): Staggered and large methyl groups are as far apart as possible.
- Stability: The Anti-conformation maximizes distances between bulky methyl groups, minimizing both torsional and steric strain.
- Result: It is the global energy minimum (most stable).
This medium difficulty chemistry question is from the chapter hydrocarbons, covering the topic of conformational analysis. It appeared in the 2025 exam.
Looking for more practice? Explore all chemistry questions or browse hydrocarbons questions on RankGuru.