{"knowledge_schema": {"broad_category": "Chemistry \u2192 Stereochemistry \u2192 Optical Activity", "refinement": "This problem involves identifying compounds that are chiral and can rotate plane-polarized light, which is a characteristic of optically active substances.", "specific_scope": "The focus is on evaluating specific organic compounds to determine their chirality and potential for optical activity.", "goal": "Identify which of the given compounds are optically active based on their structural characteristics."}, "summary": "In this problem, we are tasked with determining the optical activity of four specific compounds. Optical activity is exhibited by chiral molecules that lack an internal plane of symmetry. Among the candidates, (R)-2-butanol and (S)-1-bromo-2-chloropropane are chiral and will exhibit optical activity. In contrast, meso-tartaric acid and cis-1,2-dichlorocyclohexane are not optically active due to their internal symmetry. Therefore, two of the four compounds will exhibit optical activity."}