An electrode is a conductor through which electric current enters or leaves an electrical device.
In simpler terms, it is a metal or metallic object that is used to conduct electricity from one point to another.
Generally, two types of electrodes are known;
(i) Anode: An electrode at which an oxidation half-reaction (loss of electrons) takes place.
(ii)Cathode: An electrode at which a reduction half-reaction (gain of electrons) takes place.
An electrolyte is a substance that conducts electricity when dissolved in water or melted. When an electrolyte dissolves in water, it breaks down into ions (charged particles) that can move freely and carry an electric current.
There are generally two types of electrolytes on the basis of their strength.
(i) Strong Electrolytes: The electrolytes which Ionize almost completely in their aqueous solutions and produce more ions, are called strong electrolytes. Examples of strong electrolytes are aqueous solutions of NaCl, NaOH, and H2SO4, etc.
(ii) Weak Electrolytes: The electrolytes which ionise to a small extent when dissolved in water and could not produce more ions are called weak electrolytes. Acetic acid (CH3COOH) and Ca(OH)2when dissolved in water, ionise to a small extent and are good examples of weak electrolytes.
The substances, which do not ionise in their aqueous solutions and do not allow the current to pass through their solutions, are called non-electrolytes.
Sugar Solution and Benzene are non-electrolytes.
The device which converts electrical energy into chemical energy and vice versa by using a redox reaction
An electrochemical cell consists of two electrodes. Each electrode is in contact with an electrolyte; the electrode and the electrolyte make up a half-cell. A wire connects the two electrodes, and a porous barrier or salt bridge(2) separates the two electrolytes.
Electrochemical cells are of two types:
(i) Electrolytic cells
(ii) Galvanic or voltaic cells
A device in which an external source of electrical energy does work on a chemical system, turning reactant(s) into the higher-energy product(s).
In this cell, an external source of electrical energy is applied to the cell and causes a nonspontaneous reaction to occur inside it. In such a cell, electrical energy is converted into chemical energy as low-energy reactants form higher-energy products. A reaction that is driven in this way, by the consumption of electrical energy, is called electrolysis; a cell in which electrolysis occurs is called an electrolytic cell. In electrolytic cells, electrons are pumped into the cathodes (making them the negative electrodes), and out from the anodes (making them the positive electrodes).
An electrochemical cell in which chemical energy is transformed into electrical work by a spontaneous cell reaction.
Batteries and fuel cells are two types of voltaic cells.
