Question

Explain ion-dipole interaction with suitable examples.

Answer 1

Hint: We know that intermolecular forces are electrostatic in nature and include van der Waals forces and hydrogen bonds. Molecules in liquids are bonded to other molecules by intermolecular interactions that are weaker than the intramolecular interactions that hold the atoms together within molecules and polyatomic ions. The three major types of intermolecular interactions are,
-Dipole-dipole interactions
-London dispersion forces
-Hydrogen bonds

Complete step by step answer:

The ion-dipole interactions are similar to van der Waals interactions of neutral molecules that refer to weak non-covalent bonds. This is because of interactions between ions and polar groups of molecules (or induced dipoles).
Ion-dipole forces are stronger than dipole interactions because the charge of any ion is much higher than the charge of a dipole; the strength of the ion-dipole force is proportionate to ion charge.
An ion-dipole force contains an ion and a polar molecule aligning so that the positive and negative charges are next to each other, permitting for maximum attraction.
Ion-dipole forces are most commonly found in solutions especially essential for solutions of ionic compounds in polar liquids.
A positive ion (cation) gets attracted to the partially negative end of a neutral polar molecule.
A negative ion (anion) gets attracted to the partially positive end of a neutral polar molecule.
Ion-dipole attractions become stronger as either the charge on the ion rises, or as the magnitude of the dipole of the polar molecule increases.
In simple words, an ion-dipole force is an attractive force, which results from the electrostatic attraction taking place between an ion and a neutral molecule that contains a dipole.
For example: Ion-dipole forces are generated between polar water molecules and sodium ions. The oxygen atom in the water molecule contains a slight negative charge and gets attracted to the sodium ion that is positive. These intermolecular ion-dipole forces are weaker than covalent or ionic bonds.

Note:
A few other intermolecular forces are,
-London Dispersion forces: London dispersion forces are weak interactions due to the temporary changes in electron density in a molecule. All covalent compounds exhibit London dispersion forces. These intermolecular forces are the only intermolecular forces present in nonpolar compounds.
-Hydrogen Bonding: A chemical bond where a hydrogen atom of one molecule is linked to an electronegative atom like nitrogen, oxygen, or fluorine atom, usually of another molecule is known as hydrogen bonding.
-Dipole-dipole interactions: Dipole–dipole interactions are electrostatic interactions between molecules which have permanent dipoles. This interaction is stronger than the London forces but is weaker than ion-ion interaction because only partial charges are involved. The positive end of a polar molecule will attract the negative end of the other molecule and affect its position.