Final answer:
There are 4 possible stereoisomers for 2,3-dibromo-3-phenylpropanoic acid.
Step-by-step explanation:
The formula 21 tells the maximum possible number of stereoisomers of compounds having n number of chiral centers. For 2,3-dibromo-3-phenylpropanoic acid, there are two chiral centers (the two bromines) and thus the maximum number of stereoisomers would be 22 = 4.
However, not all four stereoisomers exist because some may be identical. You can determine the number of distinct stereoisomers by considering the different arrangements of substituents around each chiral center. In this case, there are two possible stereoisomers for each chiral center, resulting in a total of 2 x 2 = 4 possible stereoisomers for 2,3-dibromo-3-phenylpropanoic acid.