Electrolyte solutions play an important role in our environment, including batteries, soil, seawater, the human body, and food. The first step in understanding the properties of electrolyte solutions is to study their electrical properties. In this paper, we describe the equipment for measuring the electrical resistance of electrolyte solutions for the purpose of practical training of our students, examples of measurement, analysis and educational policy. Since the equipment is intended for practical training, the educational effect is more important than the accuracy, and it was designed and fabricated so that the equipment is compatible with the principles and circuits. By measuring the concentration dependence of electrical resistance, students find the effect that becomes more pronounced at high concentrations. They also learn the importance of accurate data processing and that they should not make preconceived measurements or data processing when faced with the unknown. When measuring the temperature dependence of electrical resistance, we will use an Arrhenius plot to obtain the energy values involved in this phenomenon. By comparing this to the energy of vaporization of water, students will have the opportunity to discuss the origin of hydrogen bonding and viscosity. From the relationship between the electrical resistance and the viscosity of water, they verify that the movement of the ion in the water is disturbed by the viscous resistance. The ionic radius is also obtained from the theoretical analysis based on this.
|
