Organic emissions from mobile sources (cars, trucks, planes, and so on) become oxidized in the troposphere and can then assist the formation of particulate secondary organic aerosols. Such small particulate matter can penetrate deep into our lungs and cause acute irritations. It has been reported that carboxylic acids, such as benzoic acid, can form stable complexes with sulfuric acid (H2SO4) in a similar manner that carboxylic acids can form dimers (Sec. 10.2). Suggest a structure for a stable complex between benzoic acid and sulfuric acid.