Standard enthalpy of formation of disodium hydrogen phosphate hexahydrate and sodium diphosphate
| Autor: | H. Gmati-Ben Khaled, Mohamed Jemal, Ismail Khattech |
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| Rok vydání: | 2011 |
| Předmět: |
Chemistry
Inorganic chemistry Infrared spectroscopy Calorimetry Atomic and Molecular Physics and Optics Standard enthalpy of formation Dilution Enthalpy change of solution Calorimeter Thermochemistry General Materials Science Physical and Theoretical Chemistry Disodium hydrogen phosphate Nuclear chemistry |
| Zdroj: | The Journal of Chemical Thermodynamics. 43:521-526 |
| ISSN: | 0021-9614 |
| DOI: | 10.1016/j.jct.2010.11.008 |
| Popis: | Commercial disodium hydrogen phosphate dodecahydrate (Na 2 HPO 4 ·12H 2 O) was used as a precursor for synthesizing disodium hydrogen phosphate hexahydrate (Na 2 HPO 4 ·6H 2 O) and sodium diphosphate (Na 4 P 2 O 7 ). The purity of the synthesized products was checked up by IR spectroscopy and X-ray diffraction. The heat of dissolution of these compounds, in acid solutions of several concentrations (w/w) of H 3 PO 4 was measured in a C-80 SETARAM calorimeter. Many dilution and mixing processes were also realized in the calorimeter in order to get the standard enthalpy of formation of these products. The values obtained for the enthalpies of formation are: (−3210.5) and (−3516.5) kJ · mol −1 for sodium diphosphate (Na 4 P 2 O 7 ) and disodium hydrogen phosphate hexahydrate (Na 2 HPO 4 ·6H 2 O), respectively. |
| Databáze: | OpenAIRE |
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