Ultrasonics and Water Structure in Urea Solutions

Ultrasonic absorption and velocity in aqueous urea solutions have been measured for concentrations up to 15m and at temperatures down to − 10°C. The velocity itself was measured at pressures up to 2000 lbs/in.2. The structural part of the absorption decreases with increasing concentration of urea, until a limiting value is reached. The slope of the velocity-vs-pressure curve as a function of temperature shows that urea solutions look like water at high temperatures. These data suggest that the net effect of dissolving urea is to cause the clusters in water to be broken up.