Examples of polar in the following topics:
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- Molecular polarity is dependent on the presence of polar covalent bonds and the molecule's three-dimensional structure.
- Such bonds are said to be 'polar' and possess partial ionic character.
- Molecular polarity: when an entire molecule, which can be made out of several covalent bonds, has a net polarity, with one end having a higher concentration of negative charge and another end having a surplus of positive charge.
- A polar molecule acts as an electric dipole which can interact with electric fields that are created artificially, or that arise from interactions with nearby ions or other polar molecules.
- The water molecule, therefore, is polar.
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- Bond polarity exists when two bonded atoms unequally share electrons, resulting in a negative and a positive end.
- Bonds can fall between one of two extremes, from completely nonpolar to completely polar.
- The terms "polar" and "nonpolar" usually refer to covalent bonds.
- To determine the polarity of a covalent bond using numerical means, find the difference between the electronegativity of the atoms; if the result is between 0.4 and 1.7, then, generally, the bond is polar covalent.
- The hydrogen fluoride (HF) molecule is polar by virtue of polar covalent bonds; in the covalent bond, electrons are displaced toward the more electronegative fluorine atom.
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- The ion-dipole force is an intermolecular attraction between an ion and a polar molecule.
- However, ion-dipole forces involve ions instead of solely polar molecules.
- An ion-induced dipole force occurs when an ion interacts with a non-polar molecule.
- Like a dipole-induced dipole force, the charge of the ion causes a distortion of the electron cloud in the non-polar molecule, causing a temporary partial charge.
- Ion-dipole forces are generated between polar water molecules and a sodium ion.
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- Although charges are usually distributed evenly between atoms in non-polar molecules, spontaneous dipoles can still occur.
- When this occurs, non-polar molecules form weak attractions with other non-polar molecules.
- Nitrogen gas (N2) is diatomic and non-polar because both nitrogen atoms have the same degree of electronegativity.
- London dispersion forces allow otherwise non-polar molecules to have attractive forces.
- Investigate the difference in the attractive force between polar and non-polar molecules.
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- Plane-polarized light is created by passing ordinary light through a polarizing device, which may be as simple as a lens taken from polarizing sun-glasses.
- Monochromatic (single wavelength) light, is polarized by a fixed polarizer next to the light source.
- In the absence of a sample, the light intensity at the detector is at a maximum when the second (movable) polarizer is set parallel to the first polarizer (α = 0º).
- András Szilágyi has created a nice animation, illustrating various kinds of polarized light.
- Compounds that rotate the plane of polarized light are termed optically active.
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- This statement indicates that a solute will dissolve best in a solvent that has a similar chemical structure; the ability for a solvent to dissolve various compounds depends primarily on its polarity.
- For example, a polar solute such as sugar is very soluble in polar water, less soluble in moderately polar methanol, and practically insoluble in non-polar solvents such as benzene.
- In contrast, a non-polar solute such as naphthalene is insoluble in water, moderately soluble in methanol, and highly soluble in benzene.
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- Such a covalent bond is polar, and will have a dipole (one end is positive and the other end negative).
- Likewise, C–Cl and C–Li bonds are both polar, but the carbon end is positive in the former and negative in the latter.
- Although there is a small electronegativity difference between carbon and hydrogen, the C–H bond is regarded as weakly polar at best, and hydrocarbons in general are considered to be non-polar compounds.
- Methane is essentially non-acidic, since the C–H bond is nearly non-polar.
- As noted above, the O–H bond of water is polar, and it is at least 25 powers of ten more acidic than methane.
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- Because of the greater electronegativity of oxygen, the carbonyl group is polar, and aldehydes and ketones have larger molecular dipole moments (D) than do alkenes.
- The resonance structures in the first diagram below illustrate this polarity, and the relative dipole moments of formaldehyde, other aldehydes and ketones confirm the stabilizing influence that alkyl substituents have on carbocations (the larger the dipole moment the greater the polar character of the carbonyl group).
- The polarity of the carbonyl group also has a profound effect on its chemical reactivity, compared with the non-polar double bonds of alkenes.
- The inherent polarity of the carbonyl group, together with its increased basicity (compared with alkenes), lowers the transition state energy for both reactions, with a resulting increase in rate.
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- Polar, protic solvents such as water and alcohols solvate anions by hydrogen bonding interactions, as shown in the diagram below.
- Polar, aprotic solvents such as DMSO (dimethyl sulfoxide), DMF (dimethylformamide) and acetonitrile do not solvate anions nearly as well as methanol, but provide good solvation of the accompanying cations.
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- This characteristic is a function of the polarity of the solvent.
- Solvent polarity has been defined and measured in several different ways, one of the most common being the dielectric constant, ε.
- When subject to the electric field of an ion, such polar molecules orient themselves to oppose the field, and in so doing they limit its reach.
- Because their functional groups are made up of polar covalent bonds, protic solvents are often polar as well.
- The dielectric constants provide a measure of solvent polarity.