To visualize the Fleming’ s left hand rule using ion species as charged particles in aqueous solution, the discharge reactions of the Daniel’ s cell and the redox reaction of Fe
2+/Fe
3+ were carried out under vertical magnetic field. A copper tube was united with a circular transparent acryl resin plate, which was employed as an electrolytic cell. A zinc or carbon rods was centrally inserted into the acryl resin plate of the cell. The cell was placed on a permanent magnets (neodymium and ferrite magnets) or an originally prepared electromagnet. The geometrical arrangement was shown in Fig. 5. The cell was filled with electrolyte solution : 0.1 mol/L CuSO
4 aqueous solution for the discharge reaction of the Daniel’ s cell and 0.1 mol/L H
2SO
4 aqueous solution containing 0.1 mol/L FeSO
4 and 0.1 mol/L Fe
2 (SO
4)
3 for the redox reaction of Fe
2+/Fe
3+. The vortex motion of the electrolyte solutions originated from the Lorentz’ s force was clearly observed as soon as the cell reactions and the redox reaction took place under the vertical magnetic field caused by the electromagnet. The vortex motion visualized Fleming’ s left hand rule. The magnitude of the vortex motion was estimated by the rotation rate (rotation number a second) . The higher the rate became, the larger the electrolytic current of the redox reaction of Fe
2+/Fe
3+or the stronger the magnetic field was, which showed the quantitative relationship of the Lorentz’ s force. On the other hand, for the Daniel’ s cell, the rate decreased accompanying a decrease of the discharge current in time. The experiment was introduced for college students as estimators.
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