Does the eclipsed conformation of ethane have a center of symmetry? If so, where is it?
The correct answer and explanation is:
The eclipsed conformation of ethane does not have a center of symmetry.
To understand this, let’s break down what a center of symmetry is and how it applies to ethane. A molecule has a center of symmetry if, for every atom in the molecule, there is an identical atom positioned at an equal distance in the opposite direction. In simpler terms, a molecule has a center of symmetry if you could imagine a point in the center, and every part of the molecule would have an identical counterpart on the opposite side of that point.
Now, let’s look at ethane. Ethane (C₂H₆) has a simple structure where two carbon atoms are single-bonded, each attached to three hydrogen atoms. When the molecule adopts an eclipsed conformation, the hydrogen atoms on each carbon are directly aligned with the hydrogen atoms on the other carbon, leading to a higher energy state due to the steric strain between the atoms.
The key point here is that the eclipsed conformation does not have a mirror symmetry through the center of the molecule. While the atoms on each carbon may appear to be symmetrically positioned, the alignment in the eclipsed conformation creates a situation where the two sides are not identical in the way required for a center of symmetry. The spatial arrangement and electronic interactions are not symmetric about any central point, which means that the molecule lacks the necessary symmetry for a center of symmetry to exist.
Therefore, the eclipsed conformation of ethane does not have a center of symmetry.