Term
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Definition
| center of mass for a molecule |
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Term
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Definition
a quantity to measure net molecular polarity
formula
µ= Q x r
Q: magnitude of charge at either end
r: distance between the charges |
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Term
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Definition
unit used when referring to dipole moment
1 D= 3.336 x 10-30 coulomb meters
(conversions may be necessary) |
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Term
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Definition
| chemical bond made possible by the transfer of electrons between two or more atoms |
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Term
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Definition
| chemical bond made possible by the sharing of electrons between 2 atoms |
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Term
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Definition
| covalent bond where the electrons are shared equally between the atoms involved |
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Term
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Definition
a scale of the tendency of an element (atom) to attract electrons
0 0.3 1.7 3.3
non-polar polar covalent ionic
covalent |
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Term
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Definition
a measure of how ionic a a covalent bond is, based on expected net polarity and measured (actual) net polarity
% ionic character: (µexperimental/ µexpected)x 100%
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Term
| ion- dipole intermolecular force |
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Definition
| occurs between ions and polar solvents (moderate strength) |
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Term
| dipole-dipole intermolecular forces |
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Definition
occurs between polar molecules (weak)
Molecules with permanent dipoles attract or repel
Poles tend to align
(+ -) (+ -) (+ -)
(- +) (- +) (- +)
(+ -) (+ -) (+ -) |
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Term
Van der Waals Force
aka London Dispersion Forces
aka instantaneous dipole effects |
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Definition
tendency of electron cloud to distort in such a way that the more electronegative end appears larger and the less electronegative end appears smaller
london force becomes stronger as the sizes of an atom or molecule increases
(weak) |
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Term
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Definition
the ease with which a molecule's electron cloud can be distorted by a nearby electric field
-very relevant to London dispersion forces |
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Term
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Definition
intermolecular bond that occurs between molecules of O-H, N-H & F-H (moderate strength)
when it comes to bonds, a molcules of greater size generally has a greater attraction. However, despite being smaller, (polar) hydrogen bonded molecules may have a stronger bond than some larger (nonpolar) molecules |
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Term
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Definition
measure of a liquid's resistance to flow
(slow as molasses!)
↑ viscosity with more hydrogen bonds (???)
↑ viscosity with stronger intermolecular forces |
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Term
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Definition
resistance of a liquid to spread out and increase its surface area
(think of drops of water piling up on a penny) |
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Term
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Definition
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Term
heat (enthalpy) of fusion
ΔHfusion |
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Definition
| amount of energy required to melt 1 mole of a substance |
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Term
heat (enthalpy) of vaporization
ΔHvap |
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Definition
| amount of energy required to vaporize 1 mole of a substance |
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Term
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Definition
the partial pressure of a gas in equilibrium w/liquid at a constant temperature
(some molecules will escape)
dependent on intermolecular forces + temperature
↓ forces= higher vapor pressure
↑ temperature= higher vapor pressure |
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Term
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Definition
| temperature at which a substance's vapor pressure equals the atmospheric pressure IN THE SUBSTANCE'S CURRENT ENVIRONMENT |
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Term
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Definition
| temperature at which the vapor pressure of a substance equals atmospheric pressure AT SEA LEVEL |
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