Tetraphenylarsonium chloride as an analytical reactant: Determination of rhenium

Standard state thermodynamic properties of aqueous sodium perrhenate using high dilution calorimetry up to 598.15K

“…The uncertainty associated with the calculation of G 2 ðT; p sat ÞÀ G 2 ð298:15 K;0:1 MPaÞ from equation (12) is mainly due to the uncertainty in estimation of the standard state partial molar volume, V 2 , at p sat . However we note that a 10% uncertainty in V 2 will result in less than 0.1% error in the standard state partial molar Gibbs free energies of transfer of NaReO 4 (aq) at the highest temperature reported here, because the contributions of V 2 to the second and third terms in Equation (12) are of opposite signs and of comparable magnitude. These standard state partial molar Gibbs free energies of transfer of NaReO 4 (aq) at p sat are also summarized in table 6.…”

“…Solid sodium perrhenate (Alfa-Aesir), was purified twice by recrystalization, dried in vacuum at temperature of 600 K, and stored in a desiccator over anhydrous calcium chloride. The perrhenate was analyzed by a gravimetric method [12]. The perrhenate content was obs.…”

Colorimetric Determination of Rhenium

“…Potassium Perrhenate. The potassium perrhenate was prepared in this laboratory and found to be 100.0% pure when analyzed by the method of Willard and Smith (10), A standard solution containing 1.00 mg. of rhenium in 1.00 ml. was prepared by placing 0.3884 gram of potassium perrhenate in a 250-ml.…”

Separation and Determination of Rhenium by Anion Exchange Using the Fluoride-Chloride System.

“…Rhenium usually occurs in molybdenum-rich materials, therefore some molybdenum carry-over must be anticipated in the above distillation procedures (12). Other selective reactions involve the precipitation of rhenium as the heptasulfide, Re2S7, as nitron perrhenate (8), and as tetraphenylarsonium perrhenate (17).…”