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Electrical Potentials and Phase Transitions of Sodium Chloride Solution
Authors: Alexandr A. Gurulev
Number of views: 294
Due to the wide distribution of salt solutions in nature (in water bodies, in soils, in vegetation,
etc.), an urgent task is to study the physicochemical processes taking place in them not only at
positive temperatures, but also at negative ones. In the present work, the study of electrokinetic
effects accompanying the crystallization of water-salt solutions was carried out using the example
of sodium chloride solution. The measurements were performed with a monotonic change in
the temperature of the sodium chloride solution at a rate of 0:28C/min with simultaneous
measurement of the EMF arising between the platinum and copper electrodes, and temperature.
As a result of the experiments, a correlation of the EMF signals in the sodium chloride solution
with the process of crystallization of the sample at the eutectic temperature was found. At this
moment, the magnitude of the EMF signal increases and then sharply tends to the minimum
value. Also, by the rate of change of the sample temperature, it is possible to determine phase
transitions in liquid and solid media. With joint thermometry and measurements of electric
potentials, it is possible to study the features of the processes of formation and destruction of
crystals in solutions.