Δμ_s^o = lim ( p_s→o) [-RT ℓn(p_s^ℓ/p_s^g)_eq]

where (p_s^ℓ/p_s^g)_eq is the Ostwald absorption coefficient and p_s^ℓ and p_s^g are respectively the molar concentrations of the solute s in the liquid and the gas phase at equilibrium.

For the temperature range studied, Δμ_s was fitted to a second degree polynomial of the form:

Δμ_s^o = -14740.4 + 52.057 t - 0.04126 t²

where t is in °C (10 < t < 50°C) and Δμ_s^o is in cal/mol (1 cal = 4.184 J).

Values of the Ostwald absorption coefficient are also reported.

Experimental Data:   (Notes on the Nomenclature)
   Method/Apparatus/Procedure:
   Solubilities were determined spectroscopically. Saturated solutions were prepared in two ways: (a) direct mixing of benzene and water for ca. 48 h, (b) dissolution of benzene through the vapor phase. Absorbances of the solutions and their vapors were measured directly at λ_max with a Model 450 Perkin-Elmer spectrophotometer with a thermostatted cell holder. Establishment of equilibrium was checked by use of special three compartment cell, details of which are given in the paper.

Source and Purity of Materials:
   (1) Fluka; puriss, 99.94%, used as received.
   (2) Distilled water, further distilled from alk. KMnO₄ and acid K₂Cr₂O₇; k, 0.8 x 10^-6 S cm^-1

Estimated Errors:
   Solubility: std. Dev. In Δµ°_s, 22.794 cal/mol.
   Temperature: ± 0.05°C