The influence of ultrasonic waves on selenium hydrosol

The influence of ultrasonic waves on selenium hydrosol prepared by the reduction of SeO₂ with sulphur dioxide and hydrazine hydrate is studied. It is observed that the sols when exposed to ultrasonic waves become unstable, and get finally completely coagulated. The sol prepared by the reduction with hydrazine hydrate is found to be more resistant to the action of ultrasonic waves which may be due to the adsorbed impurities presumably hydrazine hydrate. The specific conductivity and hydrogen ion concentration increases with the time of exposure to ultrasonic waves. The coagulation of the sol may be due to the fact that the adsorbed SeO₃ ^? ions get free by the ultrasonic energy. In the presence of non-electrolytes as ethyl alcohol or acetone the sol becomes more stable to the action of ultrasonic waves.