Experimental Data and Thermodynamic Model in the Salt–Water Ternary System (NaBO₂ + Na₂B₄O₇ + H₂O) at T = 298.15 K and p = 0.1 MPa

Abstract

Solubilities, refractive indices, densities, and pH for the ternary system (NaBO 2 + Na 2 B 4 O 7 + H 2 O) at 298.15 K were measured by the dissolution equilibrium method. The phase diagram of the ternary system was established and calculated. In the phase diagram of the ternary system of (NaBO 2 + Na 2 B 4 O 7 + H 2 O), there is one invariant point, two crystallization regions corresponding to the sodium metaborate tetrahydrate (NaBO 2 •4H 2 O), and borax (Na 2 B 4 O 7 •10H 2 O). The solubility calculation of the ternary system was carried out with three models on the basis of the Pitzer and Harvie−Weare (HW) model. The first model (model I) assumes that there is only two boron ions B(OH) 4 − and B 4 O 5 (OH) 4 2− in the solution. The second model (model II) assumes that there are four forms for boron corresponding to B(OH) 3 , B(OH) 4 − , B 3 O 3 (OH) 4 − , and B 4 O 5 (OH) 4 2− in the solution. The third model was extended from model II by adding OH − in the solution. The calculated pH data for the solution with model III are in accordance with the experimental values. The results show that the calculated data with model III are more reliable. The results of solubility calculation for the system containing borate in this study are essential for the development of universal thermodynamic models for brine systems containing borate.

Special color change mechanism of Disperse Red 60 in alkaline dyeing system

“…Borax is soluble in water and its aqueous solution is alkaline due to the hydrolysis of [B 4 O 5 (OH) 4 ] 2− , and the solution contained equal amounts of H 3 BO 3 and [B(OH) 4 ] − . And the electron deficiency of the B atom leads to the presence of sp 3 hybridization in [B 4 O 5 (OH) 4 ] 2− (B atom is the center of a tetrahedron) and sp 2 hybridization (B atom is the center of a planar triangle), 32,33 while the N atom in the dye was sp 3 hybridized. When a B-N bond was formed, there may be a B-N bond with sp 3 and sp 2 hybridization (179.6 eV).…”

Experimental and Predictive Equilibrium Thermodynamics of the Aqueous Ternary System (LiCl + CaCl2 + H2O) at T = 288.15 K

“…In addition, a series of computational expressions for the mean activity coefficient and osmotic coefficient of any electrolytes in multicomponent systems were proposed by Pitzer . Furthermore, Harvie and Weare model (HW model) was developed for conventional single-ion activity coefficients and osmotic coefficients, providing a more convenient method for solubility calculation, − which was applied in classical seawater system, even in a salt water system with a high concentration.…”

Boric acid catalysed hydrolysis of peroxyacids

“…1). 8,27–34 Evidence from potentiometric, 30,31,35,36 11 B NMR, 37 Raman, 27,28,38 DFT 27,28 and X-ray absorption studies 39 indicates the presence of polyborate species containing between two and five boron atoms, with the overall negative charge on the species ranging from zero (B(OH) 3 ) to three (B 5 O 6 (OH) 6 3− ). 32 Moreover, there is a great deal of inconsistency in the observed formation constants reported from these studies, depending on experimental conditions (particularly pH) and assumptions made as to the prevalent boron species, with reported differences of up to an order of magnitude not uncommon.…”