planar vs nonplanar

[Alexis Moran2B]

If a cycloalkane has a nonplanar conformation does that mean it has to be eclipsed? or can it be nonplanar and staggered? and can it be planar and eclipsed?

[Chem_Mod]

A molecule such as a cycloalkane is conformationally flexible. It samples all the possible conformations. It spends more time on average in more stable conformations. Therefore, it is possible the molecule spends some time in any of the possible conformations you mention. However, you should be prepared to identify and/or draw the conformation associated with the particular state you are asked to represent (i.e., most stable, all bonds staggered, most unstable, etc.).