molar conductance

Concept of electrochemistry

The branch of science which deals with the relationship between electrical energy and chemical
energy and their inter-conversion of one form to another is called electrochemistry.

The chemical changes which involve the flow of electric current are called electro chemical
changes. They are classified into two types:
• Electrolysis: The changes in which electrical energy causes chemical reaction to occur.
• Electrochemical cells: The changes in which electrical energy is produced as a result of chemical
change.

Conductors: The substances which allow the passage of electric current are called conductors.
Eg. Metals like Cu, Ag, Sn etc.

Insulators: The substances which do not allow the electric current to pass through them are called
non-conductors or insulators.
Eg. Rubber, wood, wax, wool, glass etc.

Metallic conductors: These are the metallic substances which allow the electric current to pass
through them without undergoing any chemical change. The flow of electric current in metallic
conductors is due the flow of electrons in the metal atoms.
Eg. Metals like Cu, Ag, Sn etc.

Electrolytes: These are the substances which allow the electric current to pass through them in
their molten states or in the form of there aqueous solutions and undergo chemical decomposition.
The flow of electric current through an electrolytic solution is called electrolytic conduction in
which charge is carried by ions. These substances do not conduct electricity in the solid state but
conduct electricity in the molten state or aqueous solutions due to movement of ions.
Eg. Acids, bases and salts

Non-electrolytes: The substances which do not conduct electricity either in their molten state or
through their aqueous solutions are called non-electrolytes.
Eg. Sugar, glucose, urea, ethyl alcohol etc.