Electrochemistry
2.0 Conductors and Non-Conductors
2.0 Conductors and Non-Conductors
On the basis of the ability to conduct electricity or electric current, substances are classified as follows:
1. Conductors:
Those substances which allow electric current to pass through them are classified as conductors. For example. Gold, Silver, Salt solution etc.
2. Non-conductors:
Those substances which do not allow electric current to pass through them are called as non-conductors. For example. Wood, plastic, rubber etc.
Conductors are further classified on the basis of mode of passage of electric current
$(i)$ Metallic Conductors
These conductors conduct electric current by the movement of electrons without undergoing any chemical change during this process. These can conduct electricity in molten as well as in solid state. Fro example. Metals.
$(ii)$ Electrolytic Conductors
These conductors conduct electric current through their fuse state or in the aqueous solution and not in the solid form. These are also called electrolytes. These conduct electricity by the movement of ions in the solutions.
Question 1. Electrolytes do not conduct electricity in the solid form. Justify.
Solution: For a substance to conduct electricity or to transfer electric current, it should have free electrons or ion which can carry electricity. But in case of electrolytes (in solid form) do not have free electrons and ions though they are ionic compound. It is because of the reason that oppositely charged ions are held together by the strong electrostatic force and are not free to move. When they are dissolve into the water or in any aqueous solutions, the ions split and become free to move in the solution. Due to the free electrons,they start conducting electric current. For example. $NaCl$, $KCl$ etc
There are some substances or compound which do not conduct electricity in the aqueous solution and are termed as non-electrolytes. Eg. Urea, Sucrose etc.
Electrolytes are classified into two categories on the basis of the strength of the dissociation into constituent ions:
$(i)$ Strong Electrolytes
$(ii)$ Weak Electrolytes
Strong Electrolytes: Those electrolytes which dissociates or ionize completely in the aqueous solution into its constituent ions. For example. Inorganic Salts like $NaCl$, $KCl$, Acids like $HCl$, ${H_2}S{O_4},HN{O_3}$, bases like $KOH$, $NaOH$ etc.
Weak Electrolytes: Those electrolytes which dissociates partially in the aqueous solution into its constituent ions. Generally weak acids and weak bases are weak electrolytes. For example. $C{H_3}COOH,N{H_3}$, ${H_2}C{O_3},N{H_4}OH{H_2}S$ etc.
