Question

What are intermolecular forces? Explain the role of these forces in different states of matter.

Answer 1

• Intermolecular forces are the attractive forces as well as repulsive forces present between the neighbouring molecules. 
• The attractive force decreases with the increase in distance between the molecules. 
• The intermolecular forces are strong in solids, less strong in liquids and very weak in gases. Thus, the three physical states of matter can be determined as per the strength of intermolecular forces.
• The physical properties of matter such as melting point, boiling point, vapor pressure, viscosity, evaporation, surface tension and solubility can be studied with respect to the strength of attractive intermolecular forces between the molecules.
• During the melting process, intermolecular forces are partially overcome, whereas they are overcome completely during the vapourization process.