Intermolecular Forces Flashcards
THE KINETIC MOLECULAR THEORY OF MATTER
- explains the observable properties of the states of matter
Matter is made up of
tiny particles that are constantly moving
What particles hv energy?
All
What states has least energy?
Solid
State has most energy?
Gas
A phase changr occur as the
energy of particles is increased or
decreased.
High amnt of space
Gas
Least space
Solid
5- Atoms and molecules have ?between them
attractive forces
. The
larger the space, the ? the force of attraction.
weaker
Intra
Within
? force since there is
a bond that holds the two atoms
of the same molecule together.
intramolecular
attractive force that holds the
the atoms of two molecules
together.
Intermolecular
Intermolecular is ? Than intramolecular
Weaker
The strength of interaction between molecules determines the ?,
Properties of a substance
The strength of the interaction between molecules affects the ? and ?of compounds as well as the ? of one substance to another.
melting boiling point solubility
• It also causes the compound to exist in ? at a given temperature.
certain states of matter (solid, liquid or gas)
Three types of IMF exist in neutral molecules. They are collectively known as the “
van der Waals forces,
Three types of IMF exist in neutral molecules. They are collectively known as the van der Waals forces, after the Dutch physicist ?
Johannes Diderik van der Waals
These three types are presented in order of increasing strength:
• ?
London dispersion forces
• dipole-dipole interaction
• hydrogen bonding
Londo Dispersion Forces inteoduced by
Fritz London
Most ? substances exist as ? under ordinary conditions.
nopolar gas
This is an indication that interaction between molecules of nonpolar substances is very ?.
weak
London dispersion aka
It is also known as the instantaneous dipole-induced dipole interaction.
• All ? compounds exhibit London dispersion forces.
covalent
If is the weakest IMF.
London
Although any single interaction
“, dispersion
many
Londoni
forces
creates
? force.
Weak, storng
London example
Gecko
Attractive forces between polar covalent molecules
Dipole dipole inhrraction
Hydrogen bonding
hydrogen atom bonded to O, N, or F is electrostatically attracted to an O, N, F atom in another molecule.
Hydrogen
atom
bonded to very electronegative atoms:
- oxygen. nitrogen fluorine.
strongest of the three types of IMF.
INTERMOLECULAR FORCES OF ATTRACTION
3. Hydrogen Bonding
• It is the
The ? is held together by an extensive network of hydrogen bonds.
double helix of DNA
are present in all covalent compounds.
London dispersion
present only in polar compounds with a permanent dipole
Dipole dipole interactions
occurs only in compounds that contain O-H, N-H, H-F bond.
Hydrogen bond
Dipole moment
occurs when one atom is more electronegative than another
Polar Molecule
the positive charge end will attract to the negative charge end
Molecular Geometry
Molecular Geometry – the arrangement of the atoms of molecules in space;
The ? of compounds are greatly affected by
their shape or geometry.
physical and chemical properties
The ? can help determine the geometry of
molecules. One dot = one valence electron; One dash = one single bond
Lewis electron-dot structure
Molecular Geometry – based on
ased on the VSEPR theory;
electron pairs are arranged
around a central atom in a way that they can be as ?nas possible from
each other
far apart
if
the shape of the molecule is symmetrical, it is polar or not?
Non
