Final answer:
A compound is chiral if it has no planes of symmetry and has non-superimposable mirror images, known as enantiomers. Stereocenters are typically sp³-hybridized carbon atoms with four distinct attachments. A compound with multiple stereocenters can still be achiral if it has a plane of symmetry, making it a meso compound.
Step-by-step explanation:
To determine if a compound is chiral or not, we need to identify if the compound has any planes of symmetry and the number of stereocenters. A compound is considered chiral if it lacks any planes of symmetry, meaning it's not superimposable on its mirror image. These molecules are referred to as enantiomers. A stereocenter, or a chiral center, is typically an sp³-hybridized carbon atom with four different groups attached to it. If a compound has more than one chiral center, it may still be achiral if it has a plane of symmetry, which makes it a meso compound.
For example, a compound with one stereocenter is chiral and has a pair of enantiomers. The number of possible stereoisomers for a compound with multiple stereocenters is given by 2⁺, where 'n' is the number of stereocenters. However, the actual number of stereoisomers may be less because of the presence of meso forms, which are symmetric and thus achiral. As for molecules without a chiral center, such as those with sp- or sp²-hybridized atoms, or sp³-hybridized atoms with two identical groups, they are superimposable on their mirror images and thus are not chiral.