Intermolecular forces and Physical Properties. Grade 11. Question 3. Nov 2023. GP. Paper 2.

In this video I am going to solve a question on Intermolecular Forces and the relationship between the intermolecular forces and some physical properties like boiling point, melting point and vapuor pressure. BOILING POINT: The temperature at which the vapour pressure of a substance equals atmospheric pressure. The stronger the intermolecular forces, the higher the boiling point. MELTING POINT: The temperature at which the solid and liquid phases of a substance are at equilibrium. The stronger the intermolecular forces, the higher the melting point. VAPOUR PRESSURE The pressure exerted by a vapour at equilibrium with its liquid in a closed system. The stronger the intermolecular forces, the lower the vapour pressure. Different intermolecular forces (Van der Waal's forces): (i) Dipole-dipole forces: Forces between two polar molecules (ii) Induced dipole forces or London forces: Forces between non-polar molecules. (iii) Hydrogen bonding: Forces between molecules in which hydrogen is covalently bonded to nitrogen, oxygen or fluorine – a special case of dipole-dipole forces. Find the question here: https://drive.google.com/file/d/10xAG...