Heat Effect of the Protonation of Glycine and the Enthalpies of Resolvation of Participating Chemical Species in Water–Dimethylsulfoxide Solvent Mixtures
- Authors: Isaeva V.A.1, Sharnin V.A.1
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Affiliations:
- Ivanovo State University of Chemistry and Technology
- Issue: Vol 92, No 2 (2018)
- Pages: 214-219
- Section: Chemical Thermodynamics and Thermochemistry
- URL: https://journals.rcsi.science/0036-0244/article/view/169881
- DOI: https://doi.org/10.1134/S0036024418020085
- ID: 169881
Cite item
Abstract
Enthalpies of the protonation of glycine in water‒dimethylsulfoxide (DMSO) mixed solvents are determined calorimetrically in the range of DMSO mole fractions of 0.0 to 0.9, at T = 298.15 K and an ionic strength μ = 0.3 (NaClO4). It is established that the protonation of glycine becomes more exothermic with an increasing mole fraction of DMSO, and the enthalpies of resolvation of glycine and glycinium ions in water‒DMSO solvent mixtures are calculated. It is shown that the small changes in the enthalpy of protonation observed at low mole fractions of DMSO are caused by the contributions from the solvation of proton and protonated glycine cancelling each other out. The enthalpy term of the Gibbs energy of the reaction leading to the formation of glycinium ion is estimated along with the enthalpy of resolvation of the reacting species in the water‒DMSO mixed solvent.
About the authors
V. A. Isaeva
Ivanovo State University of Chemistry and Technology
Author for correspondence.
Email: kvol1969@gmail.com
Russian Federation, Ivanovo, 153000
V. A. Sharnin
Ivanovo State University of Chemistry and Technology
Email: kvol1969@gmail.com
Russian Federation, Ivanovo, 153000