Electric current can be conducted through a liquid or liquids by the process of electrolysis.
What is electrolysis? Electrolysis can be defined as decomposition of a certain liquid and solution into their component parts when electricity is passed through them.
Electrolysis cannot be discussed without talking about electrolyte, ions, voltameter and electrodes.
What is electrolyte? It can be defined as a chemical compounds in form of liquid or solutions which decompose into its components parts when electricity is passed through them. Example are Copper tetraoxosulphate VI, Tetraoxosulphate VI acid, Sodium hydroxide, Sodium chloride and many more.
Ions. Ions can be described as positive or negative charged atom or compound. The positive ion is called cation
while negative ion is called anion
What is electrode? Can be defined as rod or plate through which current enters or leaves the electrolyte. There are positive and negative electrodes. The positive electrodes is called anode and the negative electrode is called cathode.
Voltameter. This is vessel containing electrolyte and electrode
Examples of electrolysis
1.Electrolysis of acidulated water.
Here electrolyte is water and few drop of tetraoxosulphate V1 acid. The electrodes are made up of platinum.
When steady electricity is passed through the platinum electrodes the bubbles of gases are formed at the upper end of graduated tube of Hoffmann Voltameter use in conducting electrolysis of acidulated water and the level of electrolyte fall. The hydrogen gas is collected at a cathode while the oxygen gas is collected at the anode.
Equation electrolysis of acidulated water
According to ionic theory water dissociate into hydrogen ions and hydroxyl ion. That is
H20 → H+ + OH–
The tetraoxosulphate vi acid dissociate into hydrogen ions and tetraoxosulphate vi ions which is given as
H2SO4 →2H+ + SO42–
What happens at the anode
during electrolysis of acidulated
OH– + e = OH
OH + OH = H2O
O + 0 + O2
(oxygen produced at the anode)
What happens at the cathode
during electrolysis of acidulated
H+ + e = H
H + H = H2
(Hydrogen Produced at the cathode)
In the electrolysis of acidulated water using platinum
electrodes, oxygen is form at the anode and the
hydrogen is formed at the cathode. The volume of hydrogen formed is twice
the volume of oxygen formed. This is evidence that there are as twice
as many hydrogen atoms as oxygen atom in water. And
it further confirmed that the chemical formula of water H20
2. Electrolysis of copper tetraoxosulphate (vi) solution using copper electrodes
Using an apparatus as shown in the diagram below. When electricity is being applied the copper tetraoxosulphate vi solutions dissociate into copper ions and tetraoxosulphate vi ions while water dissociate into hydrogen ions and hydroxyl
CuSO4 → Cu2+ + SO42–
H2O → 2H+ + OH–
During the passage of electricity the copper and hydrogen ions move to
cathode where copper is discharge in preference to hydrogen ion from water, therefore
copper is deposited at cathode.
And tetraoxosulphate vi ions and hydroxyl ion drift to
anode. Tetraoxosulphate vi
ion combine with copper of the anode to
form copper tetraoxosulphate vi. As
copper from the anode is going into solution so is the copper from the solution
is being deposited at the cathode. So the concentration of copper
tetraoxosulphate (VI) remains the same.
1. Electrolysis can be
used in purifying of metal
2. It is used in coating
of metal to avoid rusting
3. It is used in
generation of electricity
4. It is used in
extraction of metal
5. Electrolysis can be
used to confirm that chemical formula of water is H2O
6. It can be used in
separation of chemical compound
7. It can be used in
production or preparation of element
It can be used to produce gas from a solution