What Do We Know?
The kinetic molecular theory is a very useful model. It provides us with a molecular level understanding of the bulk properties of gases.
Pressure (p): In terms of kinetic molecular theory, pressure depends on the number of collisions between the particles in a gas sample and their container, combined with the average force exerted by each collision. An increase in the number of collisions between gas particles and their container or an increase in the average force of each collision will result in an increase in the pressure exerted by the gas sample.
Temperature (T): As stated earlier, the temperature of a gas sample is proportional to the average kinetic energy of the particles in the sample. The kinetic energy of a particle depends on the particle's mass and velocity. Therefore, particles of a certain mass that have high kinetic energy move faster than particles of the same mass that have low kinetic energy. The temperature of a gas sample is determined by the average kinetic energy of all the particles in the sample. Individual particles in the sample may have different kinetic energies, but it is the average kinetic energy of all the particles that determines temperature. Open Temperature: Molecular Level View to view a molecular level model of the movement of a sample of gas molecules as the temperature of the sample increases.
Volume (V): The kinetic molecular theory understanding of volume is essentially the same as the macroscopic understanding of volume. Volume is the space occupied by the particles of a gas. According to kinetic molecular theory the volume of a gas is the same as the volume of the container holding the gas. This is because the constant movement of gas particles causes them to fill every part of their container. Therefore, the volume and shape of the container become the volume and shape of the gas sample.
Amount (n): The macroscopic understanding of amount is very similar to amount as understood by the kinetic molecular theory. At the macroscopic level amount is measured in moles (1 mol = 6.022x1023 particles) and, at the molecular level, amount is defined by the number of individual particles present in a sample.