Dissolution of benzene, naphthalene, and biphenyl in a simulated Titan lake

We constructed a laboratory apparatus capable of measuring the saturation equilibrium concentration (csat) and dissolution rate constants (keff) of organic solutes in ethane at 94 K. We determined a csat of 18.5 ± 1.9 mg L−1, 0.159 ± 0.003 mg L−1, and 0.039 ± 0.006 mg L−1 for benzene, naphthalene, and biphenyl, respectively. The derived csat and keff can be used to predict the dissolution behavior of the materials in ethane under Titan conditions. The aromatic materials dissolved relatively quickly in liquid ethane at 94 K, reaching saturation in less than 2 h. The dissolution characteristics of benzene in ethane at 94 K are compared to those of terrestrial karst-forming materials in water at 298 K, and are used to constrain Titan surface processes. We discuss the implications of our measurements on the formation of karst on Titan, the concentration of organics in Titan’s lakes, and the formation of evaporite deposits during lake evaporation.