Refractive indices and relative permittivities of liquid mixtures of γ-butyrolactone, γ-valerolactone, δ-valerolactone, or ε-caprolactone plus benzene, plus toluene, or plus ethylbenzene at 293.15 K and 313.15 K and atmospheric pressure

The refractive indices, no, and relative permittivities, epsilon, have been measured for the binary liquid mixtures of gamma-butyrolactone, gamma-valerolactone, delta-valerolactone, or epsilon-caprolactone + benzene, + toluene, or + ethylbenzene over the whole composition range at 293.15 K and 313.15 K and atmospheric pressure. For the pure lactones the dipole moments, mu, the molar polarizability, P-M, and the molar refractivity, R-M, were determined. From the values of epsilon and n(D) of the lactone + benzene mixtures, the Kirkwood correlation factor, g, was calculated indicative of the structures of the mixtures.