{"knowledge_schema": {"broad_category": "Chemistry \u2192 Organic Chemistry \u2192 Electrophilic Aromatic Substitution", "refinement": "This problem involves understanding the effects of substituents on the benzene ring and their influence on the regioselectivity of electrophilic substitution reactions, specifically bromination.", "specific_scope": "The focus is on predicting the yield of the para-isomer in the bromination of various substituted benzene compounds, considering the directing effects of the substituents present on the ring.", "goal": "Rank the given substances based on the expected weight fraction of the yield of the para-isomer formed during the electrophilic substitution reaction with bromine."}, "summary": "This problem requires knowledge of electrophilic aromatic substitution and the influence of substituents on the regioselectivity of the reaction. The substances listed are various substituted benzene derivatives, and the task is to arrange them in order of increasing weight fraction of the para-isomer yield when reacted with bromine. The order is determined by the directing effects of the substituents: electron-donating groups favor para substitution, while electron-withdrawing groups can lead to different regioselectivity. Understanding these effects will help in ranking the substances correctly."}