THE SOLUBILITY, SPECIFIC GRAVITY AND INDEX OF REFRACTION OF AQUEOUS SOLUTIONS OF FUMARIC, MALEIC AND i-MALIC ACIDS

Abstract

2. Flocculation values for a number of electrolytes were deterrriined by the classical method.3. The chloride-free ferric oxide sol prepared was found to differ from ferric oxide sols prepared and studied by other investigators in that it followed the Burton-Bishop coagulation rule. Furthermore, it gave uniformly lower flocculation values than did these sols. By adding chloride to this chloride-free sol its behavior could be made to conform to that displayed by similar sols prepared by other investigators. The conclusion was drawn that the striking behavior of this sol was due to the absence of detectable chloride. This behavior serves to emphasize the fact that the variation of the flocculation value of anions with dilution of the sol is a function of the purity of the sol; that is, the validity or invalidity of the Burton-Bishop rule is apparently determined by the purity of the sol.

Enthalpies of solution and crystallization of fumaric acid in aqueous solution

“…The standard molar enthalpies of solution for fumaric acid of this work are comparable to the values reported by Wassermann, (1) sol H m (C 4 H 4 O 4 , T = 293.15 K) = 33.4 kJ · mol −1 and calculated from solubility measurements, (10) …”

The vapour pressure of water over saturated aqueous solutions of malic, tartaric, and citric acids, at temperatures from 288 K to 323 K

“…(6,7,11,13,17) In (28) From the knowledge of osmotic coefficients and solubility of acids in water, it is possible to determine the molar enthalpy of solution D sol H m (31) at saturation point:…”

“…In a view of the biochemical and industrial importance of aqueous solutions of hydroxycarboxylic acids (1)(2)(3)(4) their thermodynamic properties have been widely investigated, (5)(6)(7)(8)(9)(10)(11) especially in the last two decades. (12)(13)(14)(15)(16)(17)(18)(19)(20) Applying the isopiestic method, osmotic coefficients of -tartaric, meso-tartaric, and -malic acids in the molality range (0.5 to 6) mol·kg −1 have been evaluated by Robinson, Smith, and Smith (8) and over the entire molality range of citric acid by Levien.…”

Production of Fumaric Acid by Rhizopus oryzae in Simultaneous Saccharification and Fermentation using Xylo-Oligosaccharides Manufacturing Waste Residue

“…Because of the low solubility of fumaric acid at room temperature (Lange and Sinks 1930), the final culture broth was treated with 25% (w/w) NaOH solution to convert fumaric acid into soluble sodium fumarate. The excess NaOH was neutralized with 36% (w/w) H2SO4 solution before the samples were tested.…”