Fundamental thermochromic properties of buffered pH-indicator solutions and the formulation of 'athermochromic' systems

Autor:	Dean G. Hafeman, Luc J. Bousse, Kimberly L. Crawford
Rok vydání:	1993
Předmět:	Absorbance chemistry.chemical_compound Thermochromism Wavelength Solution composition Logarithm Chemistry pH indicator Proton dissociation Enthalpy General Engineering Analytical chemistry Physical and Theoretical Chemistry
Zdroj:	The Journal of Physical Chemistry. 97:3058-3066
ISSN:	1541-5740 0022-3654
DOI:	10.1021/j100114a037
Popis:	A thermodynamic basis is derived and experimentally verified for predicting the temperature-dependent spectral changes in solutions containing a pH indicator and any number of pH-buffering components. Absorbance by the acidic and basic species of the pH indicator is measured at two different wavelengths. A plot of the logarithm of the ratio of absorbances at the two wavelengths vs reciprocal temperature is a straight line with slope that varies with solution composition. The slope is used as a thermochromicity parameter to determine proton dissociation enthalpy of pH indicators and pH buffers and to calibrate solutions in «optical thermometers»
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::805ede18f0da5f3a5c0493d0fe059c22 https://doi.org/10.1021/j100114a037 Zobrazit plný text záznamu