| Hydrated rubidium pentaborate was precipitated via evaporating solution of rubidium carbonate and boric acid in stoichiometric proportions. The chemical composition and structural information about the synthesized compound were achieved using different methods of powder X-ray diffraction, Raman spectroscopy, TG/DTG/DSC and atomic absorption spectroscopy. Physicochemical property data, including density, electrical conductivity and pH data of aqueous hydrated rubidium pentaborate solutions, have been accurately determined at temperature of 298.15 and 333.15K, respectively. Furthermore, the empirical equations were used to fitting with the obtained experimental data. On the basis of these, the change rules were investigated in aqueous rubidium pentaborate solutions about the physicochemical properties when temperature and solution concentration varied. According to the equilibrium constants reported in literature and experimental pH data, besides, the type of different borate anions, content, and the speciation among different borate anions occurred in solution were studied by Newton iteration. |
