Activity coefficients of aqueous thiocyanic acid solutions from electromotive force, transference number, and freezing-point depression measurements

Abstract

Accurate values of the activity coefficients of thiocyanic acid in aqueous solution have been obtained for concentrations of up to 0.1 molal at 25 "C by combining results for transference-number experiments with those for cells with transport. The transference-number experiments were done with the movingboundary method, the transference-number at infinite dilution being calculated from measured conductivities of the thiocyanic acid. For the electromotive force (e.m.f.) measurements, conventional glass electrodes were used in conjunction with a high input-impedance electrometer.The results obtained electrochemically were checked by determining activity coefficients from freezingpoint depression measurements which also extended the range of concentrations to 1 molal.The results of the two types of measurement are in good agreement.

Ethylenediammonium chloride thiocyanate

“…For the crystal structures of related compounds, see: Kamoun et al (1989); Chen (2009). For details of the synthesis of thiocyanic acid, see: Bartlett et al (1969). For protonic conductivity and dielectric relaxation in ethylendiammonium salts, see: Karoui et al (2013).…”

“…The title compound has been obtained as crystalline solid in the reaction of ethylenediamine with an aqueous acidic mixture of hydrochloric acid and thiocyanic acid (1/1 ratio). Thiocyanic acid was prepared using the published procedure (Bartlett et al, 1969). After a slow solvent evaporation yellow crystals suitable for X-ray analysis were obtained.They were washed with diethyl ether and dried over P 2 O 5 .…”

catena-Poly[[bis(2-methoxyaniline-κN)cadmium]-di-μ-thiocyanato-κ2N:S;κ2S:N]

“…For related structures, see: Wö hlert et al (2012,2013); Bai et al (2011); Yang et al (2001). For HSCN synthesis, see: Bartlett et al (1969). For the effects of substituents on the internal angles of the benzene ring, see: Domenicano & Murray-Rust (1979).…”

“…To 25 ml of an aqueous solution of thiocyanic acid (0.8 M) prepared using the published procedure (Bartlett et al, 1969) an appropriate amount of cadmium carbonate (1.664 g, 10 mmol) was added and refluxed for 3 h. After cooling, 25 ml of methanol and 2.3 ml of a solution of 2-methoxyaniline (8.64 M) was added. The resulting solution was heated under reflux for 1 h and left to stand at ambient temperature.…”

Poly[bis(μ2-1,3-phenylenediamine-κ2N:N′)di-μ-thiocyanato-κ2N:S;κ2S:N-cadmium]

“…For related structures, see: MacGillivary et al (1994); Fujita et al (1995); Blake et al (1997); Withersby et al (1997); Tong et al (1998); Yang et al (2001); Chemli et al (2013). For the HSCN synthesis, see: Bartlett et al (1969). For the effects of substituents on the internal angles of the phenyl ring, see: Domenicano & Murray-Rust (1979).…”