Third dissociation constant of phosphoric acid in H2O and D2O from 75 to 300 °C at p = 20.4 MPa using Raman spectroscopy and a titanium-sapphire flow cell

Author(s):  
Jacy Conrad ◽  
Peter R. Tremaine

The first reported Raman spectra and ionization constants for the phosphate ion in H2O and D2O above 50 °C quantify deuterium isotope effects under hydrothermal conditions.

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 9097-9109 ◽  
Author(s):  
Nelaine Mora-Diez ◽  
Yulia Egorova ◽  
Hart Plommer ◽  
Peter R. Tremaine

The calculated difference between pKa values in H2O and D2O is in excellent agreement with experiment.


1996 ◽  
Vol 92 (24) ◽  
pp. 5047-5050 ◽  
Author(s):  
Claudia M. Lagier ◽  
David C. Apperley ◽  
Ulrich Scheler ◽  
Alejandro C. Olivieri ◽  
Robin K. Harris

1976 ◽  
Vol 54 (18) ◽  
pp. 2879-2883
Author(s):  
Jan Bron

To facilitate the interpretation of isotope effects on the ionization of weak acids in water and deuterium oxide, a comparison of these quantities with that for a standard acid is proposed. Therefore, a quantity Kr has been defined by the equation Kr = (kH/kD)/(kH′/KD′). The equilibrium constants KH and KD refer to the ionization constants in water and deuterium oxide respectively. The equilibrium constant KX′(X = H, D) refers to the acid used as a reference. An equation is derived from which it may be concluded, that for a series of acids closely similar in geometry and force field around the acidic group, a value of Kr close to unity should be obtained. To test this prediction the values of KH/KD for a series of n-alkanoic acids (N = 3–6) are compared experimentally with the value of KH/KD of acetic acid (25 °C). An emf method has been used in these measurements (quinhydrone electrode). In agreement with the theory a value for Kr close to unity has been observed.


Author(s):  
Jay Anderson ◽  
Mustafa Kansiz ◽  
Michael Lo ◽  
Curtis Marcott

Abstract Failure analysis of organics at the microscopic scale is an increasingly important requirement, with traditional analytical tools such as FTIR and Raman microscopy, having significant limitations in either spatial resolution or data quality. We introduce here a new method of obtaining Infrared microspectroscopic information, at the submicron level in reflection (far-field) mode, called Optical-Photothermal Infrared (O-PTIR) spectroscopy, that can also generate simultaneous Raman spectra, from the same spot, at the same time and with the same spatial resolution. This novel combination of these two correlative techniques can be considered to be complimentary and confirmatory, in which the IR confirms the Raman result and vice-versa, to yield more accurate and therefore more confident organic unknowns analysis.


1979 ◽  
Vol 44 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Jiří Velek ◽  
Bohumír Koutek ◽  
Milan Souček

Competitive hydration and isomerisation of the quinone methide I at 25 °C in an aqueous medium in the region of pH 2.4-13.0 was studied spectrophotometrically. The only reaction products in the studied range of pH are 4-hydroxybenzyl alcohol (II) and 4-hydroxystyrene (III). The form of the overall rate equation corresponds to a general acid-base catalysis. The mechanism of both reactions for three markedly separated pH regions is discussed on the basis of kinetic data and solvent deuterium effect.


1994 ◽  
Vol 48 (7) ◽  
pp. 875-883 ◽  
Author(s):  
Daniel R. Lombardi ◽  
Chao Wang ◽  
Bin Sun ◽  
Augustus W. Fountain ◽  
Thomas J. Vickers ◽  
...  

Raman spectra have been measured for a number of nitrates, nitrites, sulfates, ferrocyanides, and ferricyanides, both in the solid phase and in aqueous solution. Accurate locations of peak maxima are given. Limits of detection for some of the compounds are given for solutions and for solid mixtures in NaNO3. Preliminary measurements have been made on core material recovered from the storage tanks on the Hanford site in Richland, Washington. Representative spectra are presented, showing that it is possible to observe responses of individual components from measurements made directly on untreated cores, with the use of a fiberoptic sampling probe.


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