“Giredmet” Institute, Moscow, Russia:

A. N. Poсhtarev, Head of Laboratory, e-mail: ANP1945@mail.ru
M. V. Istrashkina, Senior Researcher
V. S. Kalimulin, Senior Researcher
V. E. Kartsev, Head of Scientific and Technical Complex

The article presents the results of experiments on determination of the boiling temperatures of rhenium acid at a pressure of 10,1 · 10⁵ Pa in the range of concentrations of rhenium acid equaled 9.83–89.80% of the masses. The composition of the liquid and the vapor phase determined analysis of the solutions on the content of rhenium acid method of plasma emission spectroscopy. The dependence of the specific electric conductivity of solutions of rhenium acids at the temperature 25 ^oC in the range of concentrations of 1.43–88.76 % of the mass. HReO₄. The experimental results are processed graphical method for concentration of rhenium acids 1.0–90.0% of the masses. It is shown, that the dependence of the electrical conductivity of rhenium acid is an extreme with a maximum value in the range of concentrations of 60.0–65.0% of the mass. HReO₄. Defined maximum conductivity of rhenium acid, which amounted to 404.4 cm₂/Ohm·EQ, as well as the calculated maximum conductivity of ions ReO₄^– , which amounted to 55.0 cm₂/Ohm·EQ and the number of ion transfer ReO₄^– equals 0.136. The dependence of the viscosity solutions of rhenium acids at the temperature 250 ^oC in the range of concentrations of 1.0–90.0% of the mass. HReO₄. Viscosity increases with increase in concentration of rhenium acid, reaching values of 35.5 g/cm·sec, at a concentration of rhenium acid 90% of the mass. According to experimental data determined the values of coef ficients A and B in the equation Jones – Dole, which amounted to 0.0088 1^1/2·mol^1/2 and 0.127 1·mol^–1, respectively. Calculated value of the coefficient for The Jonas ReO₄^– which was 0.058 1·mol^–1 and effective molar volume of hydrated ion ReO₄^–, which amounted to 0.0285–0.0244 1·mol^–1 depending on the concentration of rhenium acid in the solution.

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