Intermolecular Forces

Question 1

-has a fixed volume that cannot be
compressed into a smaller volume
-is rigid with a definite shape because the atoms, ions, or, molecules are in fixed positions

Answer 1

Solid

Question 2

-is flowing matter with a definite volume but an indefinite shape
-takes the shape of its container

Answer 2

Liquid

Question 3

-flowing, compressible matter that has no definite volume or shape
-spreads out to fill the space
-particles are much farther apart than they are
in solids and liquids

Answer 3

Gas

Question 4

-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.
-As they drift through the air
they are seen to wobble in zigzag paths. This was first
noticed in 1827 by Robert
Brown.

Answer 4

BROWNIAN motion

Question 5

The total KE and PE of all
atoms and molecules in a
material is called the

Answer 5

Internal energy

Question 6

-states that submicroscopic particles of all matter are in constant motion

Answer 6

Kinetic Theory of Matter

Question 7

-A particle can change direction only when it strikes the wall of its container or another gas particle
-Assumptions: Each gas particle rebounds without losing kinetic energy and without losing speed, but in a new direction
- Collisions of particles in a gas are called elastic collisions because no kinetic energy is lost

Answer 7

Kinetic Model of Gases

Question 8

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

Answer 8

Kinetic Model of Liquids

Question 9

-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
- Crystal lattice- The arrangement, which is repeated throughout the solid
- When a solid melts, its crystal lattices disintegrate and its particles lose their 3-dimensional pattern

Answer 9

Kinetic Model of Solids

Question 10

They arise from weak “electrostatic attractions” between molecules

Answer 10

Intermolecular Forces of Attraction
Called “Van der Waals Forces”

Question 11

• Occurs between polar molecules
• Polar Molecule = “Permanent Dipole” - asymmetrical molecule with polar bonds”

Answer 11

Dipole-Dipole

Question 12

-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.

Answer 12

Hydrogen Bonding

Question 12

How can you increase the chance for
Dispersion forces to be felt between
NONPOLARS?

Answer 12

High pressure/low temp. conditions

Question 13

-Only attractive forces between nonpolar molecules and noble gas atoms.
-Weakest of all intermolecular forces.

Answer 13

Dispersion Forces

Question 14

-Increase with increasing size
-Increase with increased number of electrons

Answer 14

London Dispersion Forces