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The nuclear spin relaxation times, T1 and T2, of 7Li nuclear magnetic resonance have been investigated over a wide range of temperatures in 14 mol kg–1 aqueous lithium chloride solution, whose thermal behaviour was examined with differential thermal analysis. The relaxation is mainly attributed to dipolar coupling between water protons and lithium ions, and T1 and T2 at temperatures higher than the glass transition point are governed by the translational motion of the hydrated lithium ions. The activation parameters of the motion were found to be Ea= 33.5 ± 0.8 kJ mol–1, τ0=(1.2 ± 0.5)× 10–17 s. The Ea values are similar to those for molecular self-diffusion in a plastic-crystalline phase of globular molecules.

The electrochemical kinetic parameters of the D.M.E./Zn(II) electrode reaction in aqueous solutions containing perchlorate, nitrate, chloride and bromide ions were measured at different temperatures (5-50 °C) by the modified square-wave polarographic technique. The Arrhenius activation parameters and thermodynamic quantities of the electrode reaction were determined from the temperature dependence of the rate constant and conditional potential, respectively. Empirical correlations were observed between some pairs of kinetic and thermodynamic quantities.

Kinetic parameters of electrode reactions are collected from the literature and tabulated.

The impedance behaviour of dme/depolarizer systems in the potential region of limiting current was investigated with dilute aqueous solutions of some metal salts [AgNO 3 , TlNO 3 , Cd(NO 3 ) 2 etc ] and TlOH. The capacitance/potential curves of metal salt solutions (pH 4–6) were found to be almost identical with those of ideally polarizable electrode systems. In contrast to the metal salt systems, the capacitance and resistance of the TlOH system (pH 11) showed a remarkable decrease and increase, respectively, at the potentials where a limiting current was observed. The impedance behaviour of the TlOH system, however, became similar to that of the metal salt systems by the successive addition of HClO 4 or NaClO 4 . These experimental results suggest that a normal compact double layer is formed in depolarizer solutions if the solution contains electrochemically inactive cations such as H + or Na + in concentrations higher than about 10 −5 N. Some evidence is also presented for the possible contribution of depolarizer cations to the formation of double layer. In the TlOH system a frequency dispersion was observed, which implies that the formation of interfacial layer is affected by some processes of a kinetic nature, unless the solution contains sufficient amount of electrochemically inactive cations to form a normal compact double layer.

Differential-capacitance/potential curves were measured at the interface between mercury and dilute aqueous solutions of HClO 4 , NaClO 4 , NaOH, CH 3 COOH and NH 4 OH. In the potential region near the zero-charge potential, the double-layer behaviour of these systems is in agreement with Grahame's theory. In the negatively polarized region, the double-layer capacitances of the strong electrolyte systems decrease with decreasing concentration; this result suggests that the complete formation of the compact double-layer becomes difficult in very dilute solutions. The double-layer properties of CH 3 COOH and NH 4 OH solutions were compared with those of the strong electrolyte solutions. The difference between the weak and strong electrolyte systems in the differential capacitances in the negatively polarized region is explained in terms of the dissociation field effect on weak electrolytes.

The viscosity B -coefficient, B s , of the total salt was found to be linearly related with the molal volume, V s,h ° , of the hydrated salt according to the equation, B s = aV s,h ° − b . The coefficients a and b were calculated to be 2·8 3 and 0·19 0 at 25°C and 2·6 2 and 0·20 9 at 5°C, respectively. The V s,h ° values at B s = 0, 67· 1 ml at 25°C and 79· 7 ml at 5°C, are in agreement with the theoretically estimated molal volumes of the associated water in liquid state. In the detailed structure of the B s / V s,h ° relation, uni-univalent halides form a grid in which each salt is arranged according to the order of the constituent ions in the periodic table.

–The Randies–Breyer–Bauer approach to the theory of a.c. polarography is extended to include the case of the irreversible electron transfer reaction by making use of a steady state concept. It is shown that the expression obtained by this approach is identical with the expression obtained by the Gerischer-Grahame approach and, in spite of the steady state assumption, compares favourably with the more rigorous expression of Matsuda. An expression for the polarographic alternating current is also derived for the case of the reversible electron transfer reaction which is followed by an irreversible chemical reaction at the electrode-solution interface. From this expression it is evident that the amplitude of the alternating current is dependent upon the drop time.