The branch of chemistry that deals with the relationship between electrical energy and chemical energy, along with their inter-conversion and mechanism is called electrochemistry.
Conductor and non conductors:
Those substances through which electric current can pass are called conductors. Mostly metals posses this character. Metals like Cu, Fe, Ag, Au etc, ionic salts like NaCl, PbS, acids like HCl, H2SO4 and alkalis like NaOH, KOH are some of the examples of conductors. Depending upon the ease with which they pass current, conductors are classified as poor and good conductors. Those substances though which electric current cannot pass are called non-conductors. Mostly non metals are non conductors. Sulphur, argon, sodium are some of the examples of non conductors.
Classification of conductors:
Conductors are classified into three categories on the basis of nature of the conduction:
1. Metallic conductors: Those conductors through which electricity can pass without any chemical changes are called metallic conductors. In metallic conductors, conduction takes place by the moving of free electrons under the influence of applied potential. Certain alloys, graphite, carbons, oxides are some of the examples of metallic conductor. Metallic conductors are the best conductor of the electricity.
2. Electrolytic conductors: Those conductors through conduct electricity though chemical changes are called electrolytic conductors. In electrolytic conduction, the movement of ions from one electrode to another electrode causes the flow of electric current. Generally electrolytic conductors are either ionic compounds like NaCl, CaCl2 or polar covalent compounds like HCl, CH3COOH etc.
3. Gaseous conductors: Those conductors which can conduct electricity under high potential difference at low pressure or when exposed to radiation are called gaseous conductors.
Difference between metallic conduction and electrolytic conduction:
|Metallic conduction||Electrolytic conduction|
|In this type of conduction, electricity is passed due to the movement of electrons.||In this type of conduction, electricity is passed due to the movement of ions.|
|There is no decomposition of substance.||The compound decomposes into its constituent ions.|
|Electrical conductance decrease with increase in temperature.||Electrolytic conductance increases with increase in temperature.|