title: Characterization of pH in liquid mixtures of methanol/H2O/CO2.
abstract: The presence of H2O and CO2 in enhanced-fluidity liquids changes the pH in these mixtures due to the formation of carbonic acid. The acid-base equilibria in enhanced-fluidity liquids will also be affected by the reduction in the dielectric constant with the addition of CO2. The pH of enhanced-fluidity liquid mixtures at room temperature was determined from the UV/visible absorption spectra of several pH indicators. pH values of methanol/H2O/CO2 mixtures with CO2 proportions as high as 19.2 mol% are reported. The effect of adding buffer to methanol/H2O/CO2 mixtures on pH was also studied. It was also shown that pressure variation did not significantly influence the pH of enhanced-fluidity liquids.
authors.affiliation: Department of Chemistry, Ohio State University, Columbus 43210, USA.
authors.forename: D
authors.initials: D
authors.lastname: Wen
authors.forename: S V
authors.initials: SV
authors.lastname: Olesik
mesh_terms: D002021:Buffers; D002138:Calibration; D002245:Carbon Dioxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D000432:Methanol / Q000737:chemistry*; D011786:Quality Control; D014867:Water / Q000737:chemistry*
chemical_list: D002021:Buffers; D014867:Water; D002245:Carbon Dioxide; D000432:Methanol