The dissolution of sodium chloride (NaCl) in water is primarily facilitated by ion-dipole forces. When NaCl is added to water, the solid lattice structure of NaCl starts to break apart. This occurs because the positive sodium ions (Na+) and negative chloride ions (Cl–) are attracted to the polar water molecules.
Water is a polar molecule, meaning it has a partial positive charge on one side (the hydrogen atoms) and a partial negative charge on the other (the oxygen atom). When NaCl is introduced to water, the dipoles of the water molecules interact with the ions. The positive sodium ions are attracted to the negative oxygen atoms of water molecules, while the negative chloride ions are attracted to the positive hydrogen atoms of water molecules.
This interaction between the water molecules and the ions is what pulls the Na+ and Cl– ions away from the solid and allows them to disperse throughout the solution. As a result, NaCl readily dissolves in water due to these ion-dipole attractions, demonstrating the significant role of intermolecular forces in solvation processes.