intermolecular

Examples of intermolecular in the following topics:

• The Effect of Intermolecular Forces

  • At high pressures and low temperatures, intermolecular forces between gas particles can cause significant deviation from ideal behavior.
  • Intermolecular forces describe the attraction and repulsion between particles.
  • The contribution of intermolecular forces creates deviations from ideal behavior at high pressures and low temperatures, and when the gas particles' weight becomes significant.
  • At high pressures, gas particles are forced into close proximity with one another, causing significant intermolecular interactions.
  • To correct for intermolecular forces between gas particles, J.D. van der Waals introduced a new term into the Ideal Gas Equation in 1873.

• Introduction to Intermolecular Forces

  • Indeed, many of the physical characteristics of compounds that are used to identify them (e.g. boiling points, melting points and solubilities) are due to intermolecular interactions.
  • It should be noted that there are also smaller repulsive forces between molecules that increase rapidly at very small intermolecular distances.

• Ion-Dipole Force

  • The ion-dipole force is an intermolecular attraction between an ion and a polar molecule.
  • These intermolecular ion-dipole forces are much weaker than covalent or ionic bonds.

• Dispersion Force

  • These intermolecular forces are also sometimes called "induced dipole-induced dipole" or "momentary dipole" forces.
  • London dispersion forces are part of the van der Waals forces, or weak intermolecular attractions.

• Dipole-Dipole Force

  • Dipole-dipole interactions are intermolecular attractions that result from two permanent dipoles interacting.
  • Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions).
  • Instantaneous dipole-induced dipole forces or London dispersion forces: forces caused by correlated movements of the electrons in interacting molecules, which are the weakest of intermolecular forces and are categorized as van der Waals forces.
  • Dipole–dipole interactions are a type of intermolecular attraction—attractions between two molecules.
  • In this video, Paul Andersen describes the intermolecular forces associated with dipoles.

• Intermolecular Addition Reactions

• Van der Waals Equation

  • The van der Waals equation modifies the Ideal Gas Law to correct for the excluded volume of gas particles and intermolecular attractions.
  • The gas particles are affected by the intermolecular forces acting on them, which leads to inelastic collisions between them. 
  • The term involving the constant a corrects for intermolecular attraction.

• Boiling & Melting Points

  • A clear conclusion to be drawn from this fact is that intermolecular attractive forces vary considerably, and that the boiling point of a compound is a measure of the strength of these forces.
  • Thus, in order to break the intermolecular attractions that hold the molecules of a compound in the condensed liquid state, it is necessary to increase their kinetic energy by raising the sample temperature to the characteristic boiling point of the compound.
  • The following table illustrates some of the factors that influence the strength of intermolecular attractions.
  • The distance between molecules in a crystal lattice is small and regular, with intermolecular forces serving to constrain the motion of the molecules more severely than in the liquid state.

• Cyclization by Intramolecular Addition Reactions

• Substances that Exist as Gases

  • Substances that exist in the gas phase exhibit negligible intermolecular forces.
  • These attractive forces are known as intermolecular forces.
  • An ideal gas is assumed to experience no intermolecular forces whatsoever, due to the fact that the particles of an ideal gas are moving so quickly, and are so far apart from one another, that they do not interact at all.
  • This is because under these conditions, intermolecular forces will be minimized.
  • Under standard conditions (1 atm, 273 K), a substance which exists as a gas is called a pure gas and (disregarding any substance-specific intermolecular forces or particle volume that could alter this value) has a volume of 22.4 L per mole.