Study of Ionic Interactions in Solution and Influenceof Alkyl Chain Cation – Solvent on Water Structurein Ethanol – Water Mixture by Magnetic FloatDensitometer

摘要

The densities of the binary solvent mixtures and its salt solutions have been measured by one of the recently modified techniques, namely Magnetic Float Densitometer. The partial molar volume or apparent molar volume ?_(v) and at infinite dilution are determined by ?_(v)~(0) values of solution mixtures for some tetra alkyl ammonium iodide salts from aqueous to non aqueous binary solvent mixture of Water – Ethanol system. The ?_(v) values showed positive and large for all the tetra alky ammonium salts in all the compositions of binary mixture solution. This is due to, the presence of weak ion- ion interactions between the components of the mixtures. The value of ?_(v) increases on decreasing the concentration of ethanol. The value of slope S_(v) also showed positive for Et_(4)NI and Pr_(4)NI salt solution whereas it is negative for Bu_(4)NI and Pen_(4)NI salts solution. This is due to the presence of specific molecular interactions that will lead to increase in electrostriction with the presence of water in the solution mixture.