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.