Pulse radiolytic generation of monomeric and dimeric cations of benzene, toluene, and naphthalene in aqueous acid media at room temperature and their spectrophotometric characterization is discussed. Results presented include measurements of each aromatic's solubility in H2O-H2SO4 and H2O-HClO4 media over the acidity range pH 1 to H-0 - 7.0, facile oxidative generation, and real-time identification of appropriate cationic transients with respective lambda(max) (nm) and epsilon (M-1 cm(-1)) values measured as follows: C6H6 center dot+ (443, 1145 +/- 75). C6H5CH3 center dot+ (428, 1230 +/- 90), C10H8 center dot+ (381, 3650 +/- 225, and 687, 2210 +/- 160), (C6H6)(2)(center dot+) (860, 2835 +/- 235), (C6H5CH3)(2)(center dot+) (950, 1685 +/- 155), and (C10H8)(2)(center dot+) (1040, 4170 +/- 320). Kinetic measurements reveal the respective formation rates of monomeric cations to be near-diffusion controlled. while the forward rate values for the dimeric species generation are marginally slower. The proton activity corrected pK(a) values are found to remain between -2.6 and -1.3 for the ArH center dot+ species (C6H6 center dot+ most acidic, C10H8 center dot+ least acidic), while the pK(a) values of (ArH)(2)(center dot+) species vary from -5.0 to -3.0 ((C6H6)(2)(center dot+) most acidic, (C10H8)2(center dot+) least acidic). In H-0 -5 in aqueous H2SO4, the respective stabilization energy of (C6H6)2(center dot+), (C6H5CH3)(2)(center dot+), and (C10H8)(2)(center dot+) is estimated to be 16.6, 15.0, and 13.7 kcal mol(-1). Thus, the aqueous acid solution emerges as an alternative medium for typical radical-cationic studies, while offering compatibility for the deprotonated radical characterization near neutral pH.