Study of sodium interaction with calcium nitrate and carbonate in alkali metal chloride melts by IR and Raman spectroscopy

In the IR and Raman spectra of molten eutectic mixtures of alkali metal chlorides with additions of calcium nitrate and carbonate (without the introduction of sodium), vibrations of NO₃⁻ and CO₃²⁻ groups of symmetry D _3h were detected. After the introduction of sodium metal into the melts of oxygen-containing salts in amounts equal to the stoichiometric content of oxygen-containing groups, the spectra did not show the characteristic frequencies of the NO₂⁻ group or CO₃²⁻ vibrations, which is evidence of the complete oxidation of the alkali metal accompanied by reduction of the nitrate and carbonate groups to nitrogen dioxide and carbon dioxide, respectively. The results of spectroscopic studies are presented.