intermolecular forces.pdf

intermolecular forces.pdf

• 1.
  Intermolecular Forces Definition Intermolecular forcesare the forces of attraction that exist between molecules. These forces play a crucial role in determining the physical and chemical properties of substances, such as boiling points, melting points, solubility, and viscosity. Intermolecular Forces The three main types of intermolecular forces are: 1. London dispersion forces (also known as Van der Waals forces): These forces are present in all molecules, whether they are polar or nonpolar. They arise due to temporary fluctuations in electron distribution, creating temporary dipoles. These temporary dipoles induce dipoles in neighboring molecules, resulting in attractive forces. London dispersion forces increase with increasing molecular size and shape. Substances with stronger London dispersion forces tend to have higher boiling points and melting points.
• 2.
  London Dispersion force ●London dispersion forces are the weakest intermolecular forces. ● They occur due to temporary fluctuations in electron distribution within molecules, creating temporary dipoles. ● These temporary dipoles induce dipoles in neighboring molecules, resulting in attractive forces. ● London dispersion forces increase with increasing molecular size and shape. ● Substances with stronger London dispersion forces tend to have higher boiling points and melting points. ● Examples of substances with predominant London dispersion forces include noble gases like helium and nonpolar molecules like hydrocarbons. 2 .Dipole-dipole interactions: These forces occur between polar molecules. They arise due to the attraction between the positive end of one polar molecule and the negative end of another polar molecule. Dipole-dipole interactions are stronger than London dispersion forces and contribute significantly to the physical properties of polar substances .
• 3.
  Dipole dipole interaction ●Polar molecules have an uneven distribution of electron density, resulting in a permanent dipole moment. ● The positive end of one polar molecule is attracted to the negative end of another polar molecule. ● Dipole-dipole interactions are stronger than London dispersion forces. ● These forces contribute significantly to the physical properties of polar substances. ● Examples of substances with predominant dipole-dipole interactions include hydrogen chloride (HCl) and water (H2O). 3.Hydrogen bonding: This is a special type of dipole-dipole interaction that occurs when a hydrogen atom is bonded to a highly Read more click on link… https://todaysciencewithchemistryandbiology.blogspot.com/