Chemistry Final Exam: Kinetic Molecular Theory

Use the kinetic-molecular theory to explain each of the following properties of gases:
a. expansion
b. fluidity
c. low density
d. compressibility
e. diffusion

a. gas particles move rapidly in all directions without significant attraction between them
b. the attractive forces between gas particles are insignificant so gas particles glide easily past one another
c. particles are much farther apart in the gaseous

Describe the conditions under which a real gas is most likely to behave ideally

at very high pressures and low temperatures; most likely to hold true for gases whose particles have little attraction for each other (noble gases)

How does the kinetic-molecular theory explain the pressure exerted by gases?

The greater the number of molecules, the greater the number of collisions at a constant temperature, which ultimately leads to the greater the pressure of the gas (and vice-versa)

What happens to gas particles when a gas is heated?

the particles move faster with increasing temperature and as a result, collide more

Describe the liquid state according to the kinetic-molecular theory

Liquids have the medium energy level of the three states. They have enough energy for their molecules to break free from their solid lattice but not enough to separate from being in groups of molecules. They move around slowly and randomly in groups with

Properties of liquids

Relatively high density
Relative incompressibility
Ability to diffuse
Surface tension
Evaporation and Boiling

How does the kinetic-molecular theory explain the following properties of liquids:
a. relatively high density
b. ability to diffuse
c. ability to evaporate

a. a result of the close arrangement of liquid particles
b. just like gases, the constant and random motion of particles in liquids causes diffusion. it is slower than in gases porque liquid particles are closer together
c. occurs because the particles of

Compare vaporization and evaporation

vaporization is the process by which a liquid or solid changes to a gas
evaporation is the process by which particles escape from the surface of a nonboiling liquid and enter the gas state

Describe the solid state according to the kinetic-molecular theory

particles in a solid are close together so their intermolecular forces are stronger

Account for each of the following properties of solids:
a. definite volume
b. relatively high density
c. extremely low rate of diffusion

a. particles are packed closely together
b. particles packed closer than those of a liquid or gas
c. very slow because of string attractive forces between particles in solids

What idea is the kinetic-molecular theory based on?

particles of matter are always in motion

What is an ideal gas?

a hypothetical gas that perfectly fits all the assumptions of the kinetic-molecular theory

State the 5 basic assumptions of the kinetic-molecular theory

1. Gases consist of large numbers of tiny particles that are far apart relative to their size
2. Collisions between gas particles and between particles and container walls are elastic collisions, collisions in which there is no net loss of total kinetic e

How do gases compare with liquids and solids in terms of the distance between their molecules?

gas molecules are further apart than solids or liquids because of their higher kinetic energy

What is the relationship between the temperature, speed, and kinetic energy of gas molecules?

the higher the temp, the more speed and kinetic energy the gas molecules will gain

What is diffusion? What factors affect the rate of one gas through another?

spontaneous mixing of the particles of two substances caused by their random motion
size, shape, concentration, charge, liquid solubility, and temperature

What is a fluid?

a substance that can flow and therefore take the shape of its container

What is surface tension?

a force that tends to pull adjacent parts of a liquid's surface together, thereby decreasing surface area to the smallest possible size