1164. Ultrasonic studies of electrolyte solutions. Part I. Ultrasonic velocities in solutions of inorganic salts

Abstract

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

Solvation of Ions

“…a of a liquid is related to the velocity v of sound in cm/sec for a liquid of density, p g/ml, by the equation [468,469] £ a = 1 0 V 2 p -1 b a r -1 (3.99) From â ¢ the isothermal compressibility â can be calculated using the equation a of a liquid is related to the velocity v of sound in cm/sec for a liquid of density, p g/ml, by the equation [468,469] £ a = 1 0 V 2 p -1 b a r -1 (3.99) From â ¢ the isothermal compressibility â can be calculated using the equation…”

“…Several workers have used compressibility for obtaining solvation numbers of ions [468][469][470][471][472][473][474][475][476][477].…”

“…From the compressibilities of the pure solvent and solutions the hydration numbers of the electrolytes were obtained as explained in the theory section above [468][469][470][471][472][473][474][475][476][477][478]. From the wavelengths the ultrasonic velocities in these solvents and solutions have been calculated, and from these and measured densities the adiabatic and isothermal compressibilities obtained for the solvents and solutions.…”

Molar volume and ultrasonic studies of europium soaps in mixed organic solvents

“…Many investigators (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) have used ultrasonic velocity measurements for studying ion-solvent interactions and solvation of salts in nonaqueous solvents. Many investigators (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) have used ultrasonic velocity measurements for studying ion-solvent interactions and solvation of salts in nonaqueous solvents.…”

“…The complimentary use of ultrasonic measurements can provide interesting information on the specificities of ion-solvent interactions related to the structure of solute and the reciprocal effects that arise in the solvent. Many investigators (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) have used ultrasonic velocity measurements for studying ion-solvent interactions and solvation of salts in nonaqueous solvents. However, ultrasonic measurements of soap solutions have not drawn adequate attention, even though such a study is likely to provide important information on soap-solvent and soap-soap interactions, structural changes, and soap solutions that are not ideal.…”