Electrochemistry Electrochemistry is a science that deals with the transformation of chemical energy into electrical energy or vice versa. Electrolytic conductors contain mobile ions which carry an electrical charge. when an electrical potential is applied, these ions will move in the direction appropriate to their charge. As in electronic conductance , the electrical current is a movement of electrical charge but this time the charge is carried by ions of significant mass and electrolytic conductance is accompanied by mass transfer. This property of electrolytic conduction plays a major role in some of the processes and phenomena important to metallurgist , corrosion and oxidation of metals electroplating, electrolytic extraction and refining of metals. Electrolyte :substances that are good conductors of electricity in their molten state or in their aqueous solution such as NaCl.CuSO4,acids,bases. Electrolysis :if two electronic conductors called electrodes are placed in contact with an electrolyte consisting of ions X+ and Y-and an electrical potential is applied to the electrodes by means of a battery then the positively charged ions X+ will be attracted by the negatively charged electrode and the negatively ions Y- by the positively charged electrode. The positively charged ions X+ are called cations and the negatively charged ions Y- anions. The electrode to which the cations are attracted is called the cathode, and the electrode to which the anions are attrachted is called the anode . We can define a cathode as an electrode at which electrons tend to be consumed by the discharging species and an anode as an electrode at which electrons tend to be produced as a result of the electrode reaction. In this process electrons flow from the anode to the cathode via the battery in the opposite direction to the conventional current.