# Dipole Moment

(noun)

## Definition of Dipole Moment

The vector product of the charge on either pole of a dipole and the distance separating them.

Source: Wiktionary - CC BY-SA 3.0

## Examples of Dipole Moment in the following topics:

• ### Dispersion Force

• The uneven concentration of electrons could make one side of the atom more negatively charged than the other; this creates a temporary dipole.
• Since both nitrogen atoms in the molecule have the same electronegativity, there is no dipole, and the molecule is non-polar.
• These intermolecular forces are also sometimes called "dipole-induced dipole" or "momentary dipole" forces.
• In non-polar molecules the electronic charge is evenly distributed overall; however, it is possible that at a particular moment in time, the electrons might not be evenly distributed.
• That is to say, the molecule will have a temporary dipole.
• Dispersion forces are weak intermolecular forces caused by induction of a dipole moment.
• ### Dipole Moment

• Bond dipole moment The bond dipole moment uses the idea of electric dipole moment to measure the polarity of a chemical bond within a molecule.
• For diatomic molecules there is only one (single or multiple) bond so the bond dipole moment is the molecular dipole moment, with typical values in the range of 0 to 11 D.
• At one extreme, a symmetrical molecule such as chlorine, Cl2, has zero dipole moment.
• At the other extreme, gas phase potassium bromide, KBr, which is highly ionic, has a dipole moment of 10.5 D.
• Dipole moment values can be experimentally obtained from measurement of the dielectric constant.
• A dipole exists when electrons are unequally shared between the atoms of a molecule, leading to positive and negative ends.
• ### Bond Polarity

• Polarity refers to a separation of electric charge leading to a molecule or its chemical groups having an electric dipole or multipole moment.A polar molecule acts as an electric dipole which can interact with electric fields that are created artificially or that arise from nearby ions or polar molecules.
• The magnitude of interaction with the electric field is given by the permanent electric dipole moment of the molecule.
• The dipole moment corresponding to an individual bond (or to a diatomic molecule) is given by the product of the quantity of charge displaced q and the bond length r:$\mu = q r$In SI units, q is expressed in coulombs and r in meters, so μ has the dimensions of C-m.
• If one entire electron charge is displaced by 100 pm (a typical bond length), then:$\mu = (1.6022 × 10–19 C) × (10–10 m) = 1.6 × 10–29 C-m = 4.8 D$The quantity denoted by D, the Debye unit, is still commonly used to express dipole moments.In molecules containing more than one polar bond, the molecular dipole moment is just the vector combination of what can be regarded as individual "bond dipole moments."
• H2O, by contrast, has a very large dipole moment which results from the two polar H–O components oriented at an angle of 104.5°.
• ### Dipole-Dipole Force

• For example, a water molecule has a large permanent electric dipole moment.
• Dipoledipole interactions are electrostatic interactions of permanent dipoles in molecules.
• An example of a dipoledipole interaction can be seen in hydrogen chloride (HCl): the positive end of a polar molecule will attract the negative end of the other molecule and influence their arrangement .
• Molecules often contain dipolar groups but have no overall dipole moment.
• Note that the dipoledipole interaction between two atoms is usually zero, because atoms rarely carry a permanent dipole.
• Dipole-dipole interactions are one type of intermolecular force.
• ### Heteronuclear Diatomic Molecules

• Consequently, the molecule has a large dipole moment with a negative partial charge δ– at the chlorine atom and a positive partial charge δ+ at the hydrogen atom.
• In the free carbon monoxide, a net negative charge δ- remains at the carbon end and the molecule has a small dipole moment of 0.122 D Chlorine monofluoride is a versatile fluorinating agent, converting metals and non-metals to their fluorides and releasing Cl2 in the process.
• Many of its properties are intermediate between its parent halogens, Cl2 and F2.Dipole moment has been mentioned multiple times in this atom.
•  In order to determine polarity exactly, dipole moment (in Debye) can be calculated as the product of the separated charges (q) and distance between them (r) in Angstroms:$\mu=qr$The value of q can be tricky to find, but is easily converted from the percent ionic character of a bond (just convert the percent to decimal by dividing by 100).
• ### Ion-Dipole Force

• There are four types of attractive intermolecular forces: Dipole-dipole forces: electrostatic interactions of permanent dipoles in molecules Dipole-induced dipole forces or Debye forces: the attractive interaction between a permanent multipole on one molecule with an induced (by the former di/multi-pole) multipole on another Instantaneous dipole-induced dipole forces or London dispersion forces: forces caused by correlated movements of the electrons in interacting molecules Ion-dipole forces: discussed below Ion-dipole and ion-induced-dipole forces operate much like dipole-dipole and induced-dipole interactions.
• Ion-dipole forces are stronger than dipole interactions because the charge of any ion is much greater than the charge of a dipole moment.
• Ion-dipole bonding is stronger than hydrogen bonding.
• An ion-dipole force consists of an ion and a polar molecule interacting.
• Like a dipole-induced dipole force, the charge of the ion causes a distortion of the electron cloud in the non-polar molecule .
• The ion-dipole force is an intermolecular attractive force between an ion and a polar molecule.
• ### The Structure and Properties of Water

• The presence of a charge on each of these atoms gives each water molecule a net dipole moment.
• The electrical attraction between water molecules due to this dipole pulls individual molecules closer together, making it more difficult to separate the molecules and therefore raising the boiling point.
• An object with such a charge difference is called a dipole (meaning "two poles").
• The oxygen end is partially negative, and the hydrogen end is partially positive; because of this, the direction of the dipole moment points from the oxygen towards the center between the two hydrogens.
• ### Properties of Nitrogen

• Electromagnetic Spectrum Molecular nitrogen (14N2) is largely transparent to infrared and visible radiation because it is a homonuclear molecule and, therefore, has no dipole moment to couple to electromagnetic radiation at these wavelengths.