The density, isothermal compressibility, and isobaric expansivity of Triton
X-100, a nonionogenic surfactant, and its aqueous solutions were measured
at 283, 298, and 323 K and concentrations below and above the critical conc
entration of micellation. The bulk properties of aqueous solutions of the s
urfactant were found to remain practically unaltered up to the critical con
centration of micellation.