Q1 Intermolecular Flashcards
evidence for moving particles
Brownian motion
Viewed through a microscope,
smoke can be seen to be made up
of millions of tiny bits or
particles. The bits of smoke
glint in the light from the lamp.
Brownian Motion
Viewed through a microscope,
smoke can be seen to be made up
of _______or
______. The bits of smoke
glint in the light from the lamp.
million of tiny bits or particles
As they drift through the air
they are seen to wobble in _________. This was first
noticed in _____ by ____. The effect is called
Brownian motion.
zigzag paths,
1827
Robert brown
can explain
Brownian motion – the bits of
smoke, just large enough to be
seen, have so little mass that
they are ‘jostled’ about by
thousands of surrounding gas
particles that bump into them at
random.
Kinetic Theory
Particles in solids, liquids
and gases have kinetic
energy (movement) and
stored potential energy.
_____ have the most PE.
Gases
The total KE and PE of all
atoms and molecules in a
material is called the _______. The
hotter a material, the
faster the particles move,
and the more internal
energy it has.
Internal Energy
The term ______ is
often used for both internal
energy and heat
Thermal Energy
states that submicroscopic particles of all
matter are in constant motion
Kinetic Theory
is the energy of moving
objects
Kinetic Energy
gas particle can change direction only when
it strikes the wall of its container or another
gas particle
Kinetic Model of Gases
Collisions of particles in a gas are called ______because no kinetic energy is loss
elastic collision
Particles of a liquid can slide past each
other, but they are so close together that
they don’t move as straight as gas
particles
Kinetic Model of liquid
Strong forces between particles explain the rigid structure
of solids
Particles of a solid cannot move past each other, but they
are in constant motion (vibration)
Particles occupy fixed positions in a well defined, 3-
dimensional arrangement
Kinetic Model of Solids
The arrangement, which is repeated
throughout the solid
Crystal lattice
- Called “Van der Waals Forces”
- They arise from weak “electrostatic attractions”
between molecules. - nagcoconnect sa molecules
Intermolecular forces of attraction
- Occurs between polar molecules
- Polar Molecule = “Permanent Dipole”
- asymmetrical molecule with polar bonds
- has lone pair
Dipole-Dipole attraction
Strong InterMF
Polar ( Dipole-Dipole )
- Super strong Dipole-Dipole Attraction
- Occurs when molecules have hydrogen atoms
bonded to very small, highly electronegative
atoms like F, O or N - Creates a very polar bond and an “extra polar”
molecule.
Hydrogen Bonding
Hydrogen Bonding is responsible for:
surface tension
how it beads
-weak force Only attractive forces between nonpolar
molecules and noble gas atoms.
-Weakest of all intermolecular forces.
Dispersion force
Dispersion force is also called as
induced dipole
How can you increase the chance for
Dispersion forces to be felt between NONPOLARS?
high pressure/low temp condition
(nakasisira ng IMF and high temperature, nabubuwag niya)
- Attraction between polar solvent molecules
and ions in an ionic crystal. - Allows polar solvent (like water) to “pull” the
ions into solution, creating “hydrated” ions.
molecule ion attraction
are generally soluble in polar solvents like water
Ionic compounds
