Ultrasonic behaviour of the system water + acetonitrile
Abstract
The effect of acetonitrile on the temperature of the adiabatic compressibility minimum (t.a.c.m.) and temperature of the sound velocity maximum (t.s.v.m.) of water has been studied. The structural contribution to the shift in t.a.c.m. and t.s.v.m., (ΔTβ,str.)exp. and (ΔTu, str.)exp., has been found to be positive at low concentrations, becoming maximum around X2≃0.018 and thereafter decreasing to become negative around X2≃0.045. This behaviour is explained in terms of the effects of added acetonitrile on the structure of water.