# Are monosubstituted cyclopropanes achiral or chiral?

A classmate an I were discussing the chirality of this molecule which is a monosubsituted cyclopropane. I argue this is an achiral molecule because that carbon which is bonded to bromine cannot be a stereocenter. If you try to determine a point of difference between the other two "substituents," there is none. But if you draw a mirror image, it appears to be non-superimposable which is a trademark of chiral molecules. Is my reasoning on the right track, or is there something unique about the chiral or achiral nature of cyclopropanes such as these.

It is achiral. The cyclopropane ring is planar. The substituted C will be $$\mathrm{sp^3}$$ hybridised (tetrahedral). If you consider two of the C's in one plane and the H and Br in the other plane, these two planes will make 90° angle between them and one can draw a mirror plane along the plane containing H and Br. Thus, it will be achiral.