Final answer:
To find the number of chiral carbon atoms, identify carbons with four different substituents, using atomic number priority. Examples include carbons with -Cl, -OH, -NH₂, -CH₃, and -COOH. Glucose, with four chiral carbons, demonstrates the relationship with the potential for multiple isomers.
Step-by-step explanation:
In order to determine the number of chiral carbon atoms in a molecule, one must identify the carbon atoms that are connected to four different groups or atoms. Given the examples provided, the solution involves evaluating different substituents attached to carbon atoms such as -Cl, -OH, -NH₂, -CH₃, and -COOH.
To identify chiral carbons, for instance, one should assign priority based on the atomic number of the atoms directly attached to the potential chiral center as per the Cahn-Ingold-Prelog priority rules. Then, if all four substituents are different, the carbon is chiral. For example, if a carbon is attached to -Cl (priority #1), -CH₃ tied with -CH₂CH₃ (priority #2 or #3 after resolving tiebreaker), and -H (priority #4), and all four entities are different, that carbon is chiral.
Therefore, counting the number of such carbons in the molecule in question will give us the answer to how many chiral carbon atoms are present. This is also relevant when considering the possible number of stereoisomers, which can be demonstrated by the fact that glucose, with its four chiral carbons, can have 24 = 16 isomers.