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NEET CHEMISTRYHydrocarbonsEasy

Question

The dihedral angle of the least stable conformer of ethane is:

A

60∘60^{\circ}

B

0∘0^{\circ}

C

120∘120^{\circ}

D

180∘180^{\circ}

Step-by-Step Solution

Ethane can have an infinite number of conformations due to the nearly free rotation around the carbon-carbon single bond. The two extreme conformations are the eclipsed and staggered forms. In the eclipsed conformation, the hydrogen atoms attached to the two carbons are as close together as possible. This results in maximum repulsive interaction between their electron clouds (maximum torsional strain), making it the least stable conformer . The dihedral angle (or torsional angle) in the eclipsed conformation is 0∘0^{\circ}. Conversely, the staggered conformation, where the hydrogen atoms are as far apart as possible (dihedral angle of 60∘60^{\circ}), has minimum torsional strain and is the most stable .

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Hydrocarbons. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYHydrocarbonsdihedralstableconformerethane

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