The styrene-arsenic sulfide complex initiated radical copolymerization of acrylonitrile (AN) with chromium acrylate (CrA3) at 85+/-0.1-degrees-C, using dimethylformamide (DMF) as an inert solvent, yields an alternating copolymer as evidenced by the reactivity ratios r1 = 0.1 8 and r2 = 0.03 (M1 = AN, M2 = CrA3). The kinetic equation for the system is R(p) proportional-to [As2S3]0.5[AN]1.0[CrA3]1.0. The value of the activation energy and the average value of k(p)2/k(t) are 96.2 kJ mol-1 and 1.0 x 10(-5) 1 mol-1 s-1, respectively. The properties of the resulting copolymer were studied in the form of films. Nitric acid was strongly absorbed by these films, while the absorption of hydrochloric acid was comparatively low.