Please use this identifier to cite or link to this item:
http://nopr.niscpr.res.in/handle/123456789/18886| Title: | Thermodynamic dissociation constants of glycine and dl-alanine in water- ethanol mixtures |
| Authors: | Rahman, M Ashfaqur Chowdhury, A R Zaman, M R |
| Issue Date: | May-2002 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | The thermodynamic dissociation constants of glycine and dl-alanine in 0, 20, 40, 60 and 80% (w/w) water- ethanol mixtures at 30°C and at a constant ionic strength, Is= 0.1 M KNO3 have been measured pH-metrically using Irving and Rossotti technique. pK1 and pK2 values in aqueous medium have been found to agree well with previously reported ones. It is observed that the pK1 values of these acids increase regularly with the increase of ethanol contents in the mixtures while pK2 values show distinct minima ca. at 40% (w/w) ethanol content. The variation in pK values with the solvent composition is discussed in terms of the free energy transfer from water to ethanol-water mixtures. It is concluded that the specific solute-solvent interactions play a vital role in changing the pK values in ethanol-water mixtures. |
| Page(s): | 212-217 |
| ISSN: | 0975-0991 (Online); 0971-457X (Print) |
| Appears in Collections: | IJCT Vol.09(3) [May 2002] |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJCT 9(3) 212-217.pdf | 1.36 MB | Adobe PDF | View/Open |
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.