Conductivity of N-Methylpyridinium Iodide and Its Methyl Substituted Derivatives in Water–Ethanol Mixture

Abstract

Abstract The conductivity of N-methylpyridinium iodide (NMPI) and its methyl substituted derivatives at 2-, 3-, and 4-positions in water–ethanol solvent mixtures is reported at 25°C. The conductivity data are analyzed by the Shedlovsky method to get both Λ0 and KA, the association constant, simultaneously. The Λ0 values decrease or increase with increase or decrease of the viscosity of the solvent mixtures. The values of Λ0 and K are in the order of H>3->4->2-. The Walden product Λ0η for these iodide salts behaves in a manner as is expected for highly hydrogen bonded water-alcohol mixtures. A mole fraction of 0.15 to 0.2 in ethanol indicates maximum interaction between water and ethanol. The values of Λ0 and KA indicate greater solvation and hence less ion-ion interaction in case of NMPI and 3-CH3 salts than 2- and 4-CH3 salts.