usinf the kinetic molecular theory, why does the gas pressure increase when volume of gas decreases at constant temperature?
Pressure in the vessel is caused by the molecules of the gas impinging on the walls of the vessel. As the volume is decreased, there are more molecules in the same volume (that is the concentration of the gas is increasing), therefore, more molecules are hitting the walls of the vessel and this is an increase in pressure.
According to the kinetic molecular theory, the behavior of a gas can be explained by assuming that it consists of a large number of tiny particles, such as atoms or molecules, in constant random motion. When the volume of a gas decreases at a constant temperature, the particles become more confined in a smaller space, resulting in an increase in the pressure exerted by the gas.
To understand this, we can break it down into a few key principles of the kinetic molecular theory:
1. Gas particles are in constant motion: Gas particles move in straight lines motion until they collide with each other or with the walls of the container.
2. Gas particles have negligible volume: Gas particles are extremely small and have negligible volume compared to the overall volume of the gas. This means that the particles themselves do not contribute significantly to the overall volume of the gas.
3. Gas particles exhibit elastic collisions: When gas particles collide with each other or with the container walls, they do so without losing any of their kinetic energy. This means that the total energy of the system remains constant.
Now, let's consider what happens when the volume of a gas is decreased while keeping the temperature constant:
1. As the volume decreases, the available space for the gas particles to move around also decreases. This means that the particles collide with each other and with the container walls more frequently.
2. Since the collisions between gas particles and the container walls result in a change in momentum, an increased number of collisions leads to a higher frequency of momentum changes, which in turn leads to an increase in pressure.
3. Additionally, the decrease in volume means that the gas particles bounce back from the walls more frequently, causing an increase in the force exerted by the gas on the container walls, resulting in an increase in pressure.
Overall, based on the principles of the kinetic molecular theory, when the volume of a gas decreases at a constant temperature, the gas particles become more confined in a smaller space, leading to an increase in the number and frequency of collisions with the container walls, which in turn results in an increase in the pressure of the gas.