Question

Which of the following is an anti conformation for butane?

1) Eclipsed conformation
2) Staggered conformation
3) Chair conformation
4) Boat conformation

Answer 1

The anti-conformation for butane is the staggered conformation, which has the lowest energy and is the most stable.

Step-by-step explanation:

The anti-conformation for butane is the staggered conformation.

In butane, the anti-conformation refers to the arrangement of the methyl groups (-CH3) in which they are positioned opposite to each other. This conformation has the lowest energy and is the most stable compared to other conformations like the eclipsed and gauche conformations.

The eclipsed conformation is higher in energy, as the methyl groups are positioned directly above each other, causing steric repulsion. The chair and boat conformations are not applicable to butane, but rather to cyclohexane.

Answer 2

The anti conformation for butane is represented by the staggered conformation, which is the most stable arrangement for butane molecules. So, the correct option is 2) Staggered conformation.

Step-by-step explanation:

In chemistry, understanding the conformations of butane is important for grasping how molecules behave in different spatial orientations. The anti conformation is a specific type of staggered conformation where the two largest groups (usually methyl groups in butane) are 180° apart from each other on the C2-C3 bond, minimizing steric repulsion and hence is the most stable conformation of butane. Thus, when asked which of the listed conformations is the anti conformation for butane, the correct option is 2) Staggered conformation. The other listed conformations, including eclipsed, chair, and boat, represent different spatial arrangements but do not specifically describe the anti conformation in alkanes like butane.

So, the correct option is 2) Staggered conformation.