Chemical Science International Journal

Study of Ionic Interactions in Solution and Influence of Alkyl Chain Cation – Solvent on Water Structure in Ethanol – Water Mixture by Magnetic Float Densitometer

Indu Saxena *

Department of Chemistry, University of Lucknow, Lucknow -226007, India

Rikkam Devi

Department of Chemistry, University of Lucknow, Lucknow -226007, India

Vijay Kumar

Department of Chemistry, University of Lucknow, Lucknow -226007, India

Sadhana Gautam

Department of Chemistry, University of Lucknow, Lucknow -226007, India

*Author to whom correspondence should be addressed.

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Abstract

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 ϕ_v and at infinite dilution are determined by ϕ_v⁰ values of solution mixtures for some tetra alkyl ammonium iodide salts from aqueous to non aqueous binary solvent mixture of Water – Ethanol system. The ϕ_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 ϕ_v increases on decreasing the concentration of ethanol. The value of slope S_v also showed positive for Et₄NI and Pr₄NI salt solution whereas it is negative for Bu₄NI and Pen₄NI 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.

Keywords: Magnetic float densitometer, tetra alkyl ammonium iodide salts, binary mixture, ethanol – water, apparent molar volume (ϕv)

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