PROPERTIES OF GASES

·Gases are the least dense and most mobile of the three phases of matter.
· Particles of matter in the gas phase are spaced far apart from one another and move
rapidly and collide with each other often.
· Gases occupy much greater space than the same amount of liquid or solid. This
is because the gas particles are spaced apart from one another and are therefore
compressible. Solid or liquid particles are spaced much closer and cannot be
compressed further.
· Gases are characterized by four properties. These are:
1. Pressure (P).
2. Volume (V)
3. Temperature (T)
4. Amount (n)
KineticMolecular
Theory of Gases
· Scientists use the kineticmolecular
theory (KMT) to describe the behavior of gases.
The KMT consists of several postulates:
1. Gases consist of small particles (atoms or molecules) that move randomly
with rapid velocities.
2. Gas particles have little attraction for one another. Therefore, attractive
forces between gas molecules can be ignored.
3. The distance between the particles is large compared to their size. Therefore
the volume occupied by gas molecules is small compared to the volume of the
gas.
4. Gas particles move in straight lines and collide with each other and the
container frequently. The force of collisions of the gas particles with the
walls of the container causes pressure.
5. The average kinetic energy of gas molecules is directly proportional to the
absolute temperature (Kelvin).