Question

Differentiate between ionic and covalent bonding on the basis of the following parameters:

(a) formation
(b) physical state
(c) melting and boiling points
(d) solubility
(e) electrical conductivity

Answer 1

	Ionic bonding	Covalent bonding
Formation	Ionic bond is formed by the transfer of electrons from an electropositive element to an electronegative element or between the elements with large electronegativity difference.	Covalent bond is formed by the sharing of electrons between two non-metals or between the elements with negligible electronegativity difference.
Physical state	Ionic compounds are formed by the transfer of electrons due to which cations and anions are formed.These oppositely charged ions are held by strong electrostatic forces of attraction to keep them in fixed positions.This results in the close packing of ions and hence are strong crystalline solids.	Covalent compounds are formed by the sharing of electrons and the constituent particles like atoms or molecules are held by weak Van der waal's forces.Due to the weak attractive forces, particles are held loosely and hence, the covalent molecules exist as liquids or gases.
Melting and boiling points	Ionic compounds contain oppositely charged ions held by strong electrostatic forces of attraction and exist as crystalline solids.In order to break these molecules, a large amount of energy is required.Hence, ionic compounds have high melting and boiling points.	Covalent compounds contain atoms or molecules held by weak Van der waal's forces of attraction and exist as amorphous solids or liquids or gases.In order to break these molecules, a relatively less amount of energy is required. Hence, covalent compounds have low melting and boiling points.
Solubility	Ionic compounds are highly polar in nature due to the presence of oppositely charged ions and hence can readily dissolve in polar solvents like water.	Covalent compounds can slightly polar like $HCl$ or non-polar in nature like $Cl-Cl$ due to the absence of oppositely charged ions and hence can readily dissolve in non-polar solvents like chloroform, benzene etc.
Electrical conductivity	Ionic compounds like $NaCl$when dissolved in water forms cations and anions like $N{a}^{+}\&C{l}^{-}$respectively and these conduct electricity effectively.Hence, ionic compounds in molten state or fused state or aqueous state are good conductors of electricity.	Covalent compounds like $C_6{H}_{12}{O}_6$ when dissolved in water do not form any ions and do not conduct electricity .Hence, covalent compounds act as bad conductors of electricity.