Question

Explain the covalent character in ionic bond.

Answer 1

1. Like the partial ionic character in covalent compounds, ionic compounds show partial covalent character. For example, the ionic compound, lithium chloride shows a covalent character and is soluble in organic solvents such as ethanol.
2. The partial covalent character in ionic compounds can be explained on the basis of a phenomenon called polarisation. We know that in an ionic compound, there is an electrostatic attractive force between the cation and anion. The positively charged cation attracts the valence electrons of anion while repelling the nucleus.
3. This causes a distortion in the electron cloud of the anion and its electron density shift towards the cation, which results in some sharing of the valence electrons between these ions. Thus, a partial covalent character is developed between them. This phenomenon is called polarisation.
4. The ability of a cation to polarise an anion is called its polarising ability and the tendency of an anion to get polarised is called its polarisability.