Electrodes made from pencil lead are attached to a 9V battery to electrolyze various solutions. Oxidation occurs and the anode and reduction occurs at the cathode. When a solution of tin (II) chloride is electrolyzed tin metal and chlorine gas are produced:
SnCl2 (aq) → Sn (s) + Cl2 (g)
When a solution of copper (II) chloride is electrolyzed copper metal and chlorine gas are produced:
CuCl2 aq) → Cu (s) + Cl2 (g)
When electricity is passed through a pickle, it is conducted through Na+ and the Cl- ions that are present in the pickle. The electricity excites the electrons to a higher energy state, and when the fall back to ground state they emit a yellow/orange light.