1. Spectroscopic Study of Aqueous H2SO4 at Different Temperatures and Compositions: Variations in Dissociation and Optical Properties
- Author
-
Cathrine Lund Myhre, Claus J. Nielsen, Daniel H. Christensen, and Flemming M. Nicolaisen
- Subjects
Molality ,Aqueous solution ,Chemistry ,law ,Analytical chemistry ,Ionic bonding ,Specular reflection ,Physical and Theoretical Chemistry ,Crystallization ,Refractive index ,Spectral line ,Dissociation (chemistry) ,law.invention - Abstract
The ionic speciation and the optical properties of aqueous H2SO4 have been investigated as a function of temperature and acid concentration by spectroscopic techniques. FT-Raman spectra have been obtained of 1.43−44.04 molal (12−81 wt %) aqueous H2SO4 in the temperature region from 300 to 220 K. The degree of dissociation of the second dissociation step in aqueous H2SO4 (α2: HSO4- ⇄ H+ + SO42-) is derived from the relative intensities of the HSO4- Raman bands around 1050 cm-1 versus the SO42- band around 980 cm-1, and a polynomial parametrization of α2 is presented. FT-IR specular reflectance spectra are obtained of 6.46−44.04 molal (38−81 wt %) aqueous H2SO4 in the temperature region from 300 K to as far down as possible before crystallization by freezing occurred. The complex index of refraction is obtained from the IR reflectance spectra by the use of the Kramers−Kronig transformation, and the importance of including far-infrared data in the transformation is demonstrated. A revised parametrization of...
- Published
- 2003