Intermolecular forces Flashcards
These are electrostatic interactions between
permanently or transiently (temporarily) charged
chemical species.
Intermolecular Forces
They refer only to attractive interactions, which hold
molecules and ions together in condensed phases
(liquid and solid).
Intermolecular Forces
Intermolecular Forces govern many of the bulk physicals
properties of substances and mixtures, such as
______________________
melting point, boiling point, and surface tension.
These forces govern many of the bulk physical
properties of substances and mixtures, such as
melting point, boiling point, and surface tension.
Intermolecular Forces
TYPES OF INTERMOLECULAR FORCES?
- London Dispersion Forces (Van der Waals)
- Dipole to Dipole Forces (Van der Waals)
- Ion – Dipole Forces
ION-ION FORCES, also known as __________
IONIC BONDING.
These forces arise from the electrostatic attraction between two ions with opposite charges.
IONIC BONDING.
Ionic Bonding Arises from what?
the electrostatic attraction between two ions with opposite charges.
Intermolecular forces only refers to?
Attractive Interactions
Attractive interactions does what?
hold molecules and ions together in condensed phases
They are not technically considered intermolecular forces, but are a helpful starting point for understanding the true IMFs (intermolecular forces).
Ionic Bonding
They are not technically considered intermolecular forces but are a helpful starting point for understanding the true IMFs (intermolecular forces).
Ionic Bonding
Ionic Bonds are not technically?
Intermolecular Forces
Are also generally stronger than the IMFs, which is why most
pure salts are solids except at extremely high temperatures.
Ionic bonds
pure salts are solids except at?
extremely high temperatures.
Table salt has a melting point of?
800 degrees Celcius
WEAKEST intermolecular forces
London Dispersion Forces
✓ The more electrons a molecule has, the stronger the what?
London dispersion
forces are.
The breaking of London dispersion forces doesn’t require that much what?
Energy
All molecules experience London Dispersion Forces (LDFs).true or false?
True
Are the only IMFs that exist between noble gases and
molecules that are non-polar.
Dispersion Forces
These forces occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule.
Dipole to Dipole Forces
These forces occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule.
Dipole to Dipole Forces
Are the STRONGEST
the intermolecular force of attraction.
DIPOLE-DIPOLE INTERACTIONS
a special kind of dipole-dipole interaction that occurs specifically between a
hydrogen atom bonded to either an OXYGEN, NITROGEN, OR FLUORINE ATOM.
Hydrogen Bonding
Is a relatively strong force of attraction between molecules, and
considerable energy is required to break hydrogen bonds.
Hydrogen Bonding
Are responsible for holding nucleotide bases together in DNA and RNA.
hydrogen bonds
Attraction between an ion and a polar molecule.
Ion
Ions are very similar to ionic bonds, but
tend to be weaker because polar molecules only possess _________________, which generates less electrostatic attraction.
partial
electric charge
Because of these forces, polar solvents are better able to dissolve
____________ such as NaCl, compared with nonpolar solvents.
ionic solids
Are better able to dissolve
ionic solids
polar solvents
Because of these forces, polar solvents are better able to dissolve
ionic solids such as NaCl, compared with nonpolar solvents.
Ion
there is no what?
permanent dipole on the molecule.
Can induce a dipole in the neighbouring
molecule, which then interacts with the original transient dipole.
Transient dipole
PROPERTIES OF SUBSTANCES AFFECTED BY
INTERMOLECULAR FORCES (IMFs)
- VISCOSITY
- SURFACE TENSION
- BOILING POINT
- MELTING POINT
- SOLUBILITY
This is a measure of its resistance to flow of a liquid.
VISCOSITY
The more structurally complex are the molecules in a liquid and __________________, the more difficult it is for them to move past each
other and the________________
the stronger the IMFs between them, greater is the viscosity of the liquid.
This is the energy required to increase the surface area of a
liquid, or the force required to increase the length of a liquid surface by a given amount.
SURFACE TENSION
Surface tension results from the ____________ between molecules
at the surface of a liquid, and it causes the surface of a liquid to
behave like a stretched rubber membrane.
Cohesive forces
Force attracting water
molecules to each other.
Cohesion
capillary action—when a liquid flows within a
porous material due to the attraction of the liquid molecules to the
the surface of the material and to other liquid molecules.
Capillary Action
can also
occur when one
end of a small
diameter tube is
immersed in a
liquid.
Capillary Action
is the temperature at which the vapor pressure
becomes equal to the pressure exerted on the surface of the liquid.
Boiling Point
as bonds become more
polarized, the charges on the atoms become _______, which leads to
_____________, which leads to___________________
greater, greater intermolecular attractions, higher boiling and
melting points.
The rule “______________” is applied on the concept of
SOLUBILITY of molecules.
like dissolves like
Polar solutes dissolve in _____________
Polar solvent
nonpolar solutes dissolve in __________.
nonpolar solvents
