A theoretical study on calculation of ionic radii using limiting equivalent conductivities

Abstract

Graphs of the total radius (the distance between an anionic nuclei and a cationic nuclei in a crystal) of sodium halides and alkali metal fluorides versus total limiting equivalent conductivities were plotted. For the hard ions Na + and F − , whose behaviour approaches a hard spherical model, it was determined that radii values could be obtained using differences in limiting equivalent conductivities and ionic crystal data. From the determined radii of sodium and fluoride ions and known crystal data, radii of other alkali metal halides were calculated.

A theoretical study on calculation of absolute hydration enthalpies for some univalent ions

“…and r F À ir Na þ , l F À il Na þ (where l F À and l Na þ denote limiting equivalent conductivity of fluoride and sodium respectively), it can be seen that the viscosity of the near environment of sodium ion is higher than the viscosity of fluoride ion environment [5].…”

“…By using data of r Na þ þ r F À ð Þþ r F À À r Na þ ð Þ¼2:31 þ 0:07 (where r F À ; r Na þ denote radius of fluoride and sodium ions, respectively), the hydration enthalpy of NaF $H NaF ð Þ as 215.23 kcal/mol from curve a was found. Similarly, using data of r Na þ þ r F À ð ÞÀ r F À À ð r Na þ Þ ¼ 2:31 À 0:07, the hydration enthalpy of NaF $H NaF ð Þ as 225.96 kcal/mol from curve b was found [5]. 1 By the help of the difference in anion hydration enthalpy (ΔΔH anion =4.37 kcal/mol) and difference in cation hydration enthalpy (ΔΔH cation =−6.36 kcal/mol) found from curve a and b, versus r F À À r Na þ ð Þ¼$r, the average absolute enthalpy value of $H Na þ À$H F À ð Þ were found as 5.36 kcal/ mol.…”

“…Both sodium and fluoride ions have a hard spherical structure, and they hardly get affected by external factors. Therefore, in this work, sodium and fluoride ions were selected to be the principle ions for investigation [5] …”

Effect of styrene–acrylonitrile content on 0.5 M NaI/0.05 M I2 liquid electrolyte encapsulation for dye-sensitized solar cells

“…In this calculation, the shapes of I¯and I 3¯a re assumed to be spheres that have a constant radius of 2.11 [22] and 104 Å [2], respectively. It is clear that the D of I 3¯i s considerably smaller than that of I¯due to movement restrictions brought about by its ionic size [23].…”