Two types of ultrasonic interferometer have been constructed and used to measure the wavelengths of ultrasonic standing waves in solutions of inorganic salts in water, methanol, and ethanol, and also in the pure solvents. Ultrasonic velocities have been calculated from these measurements. THERE have been several previous studies of the passage of ultrasonic (compressional) waves through aqueous electrolyte solutions ;I* 2 however, no systematic investigation, comparing the results for a range of solutes in different solvents, has been reported. As part of a study of the solvation and structure-changing effects of ions in polar solvents, we have measured the velocities of ultrasonic waves in the following solutions : LiCl a,m NaCl a,m KC1 a NH4Cl a,m MgCl2 a AgN03 a LiBr a,m,e NaBr a,m,e KBr a,m NH4Br a,m,e MgS04 a LiI a,m,e NaI a,m,e KI a,m NH41 a,m,e LiN03 a,m,e NaN03 a,m KNO3 a NHgN03 a,m,e a, aqueous solution; m, methanol solution; e, ethanol solution.
EXPERIMENTALApparatus.-Two different types of ultrasonic interferometer have been constructed, and areThe first type, shown in Fig. 1, is generally similar to that described by Hubbard and Loomis.4 now briefly described ; further details of their construction are given elsewhere.3 1
