Final answer:
The stereochemical configuration at a tetrahedral center is determined using the CIP priority rules, where 'R' or 'S' is assigned based on the priority sequence and the orientation of the groups around the chiral center.
Step-by-step explanation:
The stereochemical configuration at a tetrahedral center can be determined using the Cahn-Ingold-Prelog (CIP) priority rules. This involves assigning a priority (1 to 4) to each group attached to the chiral center based on the atomic number of the atoms directly bonded to it. When the lowest priority group (4) is pointing away from the viewer, the configuration is denoted as 'R' if the sequence 1-2-3 is clockwise or as 'S' if the sequence is counterclockwise. If the lowest priority group is not pointing away from the viewer, you need to reverse the assignment. For example, if after assigning the correct priorities, an arrow drawn from the highest priority (1) to the second highest (2) to the third highest (3) is counterclockwise and the lowest priority group (4) is away from the viewer, then the configuration is 'S'. Conversely, if the arrow is clockwise, the configuration is 'R'. Without adequate information about the groups attached to the tetrahedral center or their priorities, it is not possible to determine the R or S stereochemical descriptors.