Question

What distinguishes a chiral carbon centre?

Answer 1

A chiral compound cannot be superimposed upon its mirror image.

Explanation:

See here for an intro...

For the importance of chiral compounds see here. As to how chiral molecules are separated, see here.

Remember for carbon, typically a `CR_1R_2R_3R_4` stereoisomer CANNOT be superimposed upon its mirror image. The experiment to separate the stereoisomers is long, and protracted, and difficult.

Answer 2

All different bonds

Explanation:

If you are looking for an easy answer, this is it:

If a carbon has four different groups attached to it, it will be chiral.