Electrons are being transferred in a redox reaction. In a voltaic cell a spontaneous reaction is occurring producing electric current. The anode is the site of oxidation in an electrochemical cell. A positive cell potential means that the free energy of the reaction in the cell is negative. Sodium metal and chlorine gas are produced in an electrolytic cell containing aqueous NaCl solution.
Tin can exist in solution as a couple of different ionic species.
H 2 and NH 3 .