Structure of aqueous solutions: Fourier transformation and band component analysis in magnesium nitrate solutions

Abstract

Abstract The polarized Raman spectra of aqueous solutions of Mg(NO 3 ) 2 have been obtained over the concentration range 0.05 m to 4.0 m. The Fourier transform of the isotropic band profile of the v 1 symmetrical stretching frequency of the nitrate ion gives evidence of more than one component. A technique is described to obtain information on the number of component bands and their relative intensities. The bands were subject to component analysis and the results are discussed in terms of three main solution species. The association constant for the formation of solvent separated ion pairs is calculated to be ∼ 2 dm 3 mol −1 . Evidence is presented for the presence of contact ion pairs at all concentrations above 2 M.