Experimental Conditions of Copper Dendrite Precipitation Under High Magnetic Field: Investigation for Visualization of Lorentz Force as Learning Material

Abstract

Metal dendrites can be valuable learning materials for the visualization of the Lorentz force in chemical reactions; however, the appropriate experimental conditions for this purpose such as the voltage, reaction time, magnitude of magnetic field, and electrolyte solution concentration are not known. Hence, we conducted experiments to effectively visualize metal dendrite precipitation in a swirling shape due to the Lorentz force generated by the magnetic field and for use as practical teaching materials. The electrolysis was carried out at a voltage of 20 V, 15 V or 10 V for 1 or 2 min with 3 or 5 rare-earth magnets in piles and a CuSO₄ aqueous solution with the concentrations of 0.050, 0.10, and 0.15 mol L^–1. It was found that the magnetic field was increased using the magnets stacked, even though the effect decreased with increasing numbers of layers. To observe the shape of the metal dendrites under a magnetic field effectively in a short time, the concentration of the aqueous CuSO₄ was determined to be 0.10 mol L^–1. The magnetic field was increased using magnets in piles, even though the effect decreased with increasing numbers of layers. A copper wire was used repeatedly as the anode, and the mass of the copper participating in the reaction gradually decreased. The magnitude of the applied voltage was not sufficiently studied in this work, and will be investigated in future studies.