2. WHAT IS ELECTROLYSIS?
Electrolysis, process by which electric current is passed through a substance to effect a
chemical change. The chemical change is one in which the substance loses or gains
an electron (oxidation or reduction). The process is carried out in an electrolytic cell, an
apparatus consisting of positive and negative electrodes held apart and dipped into a solution
containing positively and negatively charged ions. The substance to be transformed may form
the electrode, may constitute the solution, or may be dissolved in the solution. Electric current (i.
e., electrons) enters through the negatively charged electrode (cathode); components of the
solution travel to this electrode, combine with the electrons, and are transformed (reduced).
The products can be neutral elements or new molecules. Components of the solution also
travel to the other electrode (anode), give up their electrons, and are transformed (oxidized) to
neutral elements or new molecules. If the substance to be transformed is the electrode, the
reaction is often one in which the electrode dissolves by giving up electrons.
3. WHAT IS ELECTROLYSIS OF WATER ?
Electrolysis of water is a popular method used for different
applications in various industries, mainly in the food industry,
metallurgy, power plants amongst others. Besides, the
components of water which include hydrogen and oxygen
have many applications. For instance, hydrogen obtained
through electrolysis is a clean, renewable and efficient fuel
source.
The electrolysis of water is mainly carried out to yield pure
hydrogen and oxygen gases. It involves passing an electric
current through the water which results in the decomposition
4. Factors Affecting the Efficiency of Electrolysis
The efficiency of electrolysis or the electron transfer depends on
many factors such as;
i) The number of available cations and anions in the solution.
ii) Mobility rate of the ions to reach the electrode.
iii) Activation energy needed for the electron transfer from the
electrode to the electrolyte ions.
iv) The effect of the gas bubble surrounding the electrode on the
further electrotransfer etc.
Crossing over of several interfaces (solute- liquid, solute-solid,
solid-gas) results in the increase of energy requirements for the
electrolysis (overvoltage) than predicted by the thermos-
