Sound‐absorption spectra of three chemical systems (I:CO2/H2O, II:Mg++/CO2/H2O, III:Mg++/SO4=/CO2/H2O) are simulated on a computer using available, and estimated kinetic and thermodynamic data. System III is used as a simplified model for seawater and is described by a nine‐state mechanism. Using the chemical‐relaxation theory described, six nonzero relaxation times are obtained for III. The relaxation frequency and absorption amplitude of two of the times agree reasonably well with oceanic data, which indicate excess sound absorption in the 1–5‐ and 150‐kHz frequency regions.