The maximum number of stereoisomers for a molecule with n chiral centers is?

• A. 2^n
• B. n^2
• C. 2n
• D. 2n+1

Answer: (A)

Stereoisomers multiply with each added chiral center because each center has two configurations, R or S. If all centers are independent, the total number of distinct configurations is 2 × 2 × ... × 2 (n times), which is 2^n. This is the maximum possible, since symmetry or internal mirroring can create meso forms that collapse some configurations, reducing the count in real molecules. For small n, you get up to 2 for one center, up to 4 for two centers, up to 8 for three centers, and so on. The other expressions (n^2, 2n, 2n+1) don’t capture this exponential growth and don’t align with the combinatorial possibilities as n increases.