Ultrasonic velocities (u), densities (rho), viscosities (eta), relative permittivities (epsilon), and refractive indicies (n(D)) of mixtures of acetonitrile with dimethylacetamide, dimethyl sulfoxide, nitrobenzene, and methanol have been measured at 25 degrees C. From u, rho, and eta, isentropic compressibilities (kappa(B)), and its deviation from ideal behavior (kappa(s)(E)), and excess viscosities (Delta eta) have been computed. From n(D) and epsilon, the Kirkwood correlation factor, g, has also been evaluated.