Question

Use the kinetic-molecular theory to explain the change in gas pressure that results from warming a sample of gas.

Short answer

Increasing temperature increases particle kinetic energy, leading to more frequent and forceful collisions, thus raising gas pressure.

Step-by-step solution

- Understand Kinetic-Molecular Theory

The kinetic-molecular theory describes the behavior of gas particles. It states that gas particles are in constant motion and the temperature of the gas is directly related to the average kinetic energy of the particles.

- Relate Temperature to Kinetic Energy

When the temperature of a gas increases, the average kinetic energy of the gas particles also increases. This means the particles move faster.

- Explain Particle Collisions

Faster-moving gas particles collide with the walls of their container more frequently and with greater force. Each collision exerts a small amount of pressure on the walls of the container.

- Connect Collisions to Pressure

As the frequency and force of collisions increase due to higher kinetic energy, the overall pressure exerted by the gas on its container also increases.

Key concepts

Gas pressure

The concept of gas pressure is essential in understanding the behavior of gases. Pressure is defined as the force exerted per unit area on the walls of the container by the gas particles. This force comes from the particles as they collide with the walls. Gas pressure can be influenced by several factors, such as the number of gas particles, the volume of the container, and the temperature. When particles collide with the walls more frequently and with more force, the pressure increases. In general, gas pressure is a direct result of these collisions. By understanding the frequency and impact of these collisions, it's easier to comprehend how changes in conditions like temperature can affect the pressure.

Temperature and kinetic energy

Temperature is directly connected to the kinetic energy of gas particles. Kinetic energy refers to the energy of motion. For gas particles, it translates to how fast they move. According to the kinetic-molecular theory, the temperature of a gas is a measure of the average kinetic energy of its particles. This means that when you heat a gas, its particles gain more energy and move faster.
For instance, raising the temperature of a gas sample increases its average kinetic energy. As a result, the gas particles move faster and collide more vigorously with one another and with the container walls. This increased movement and collision frequency directly contribute to higher pressure within the container. Simply put, hotter gases have particles zooming around more energetically than cooler gases.
Overall, understanding this relationship between temperature and kinetic energy can help explain a wide array of gas behaviors and properties.

Particle collisions

Collisions among gas particles and between particles and container walls play a critical role in creating gas pressure. These collisions are elastic, meaning that the total kinetic energy is conserved when particles hit each other.
When the temperature of a gas increases, particles move faster and collide more frequently and forcefully. Each time a gas particle hits the wall of the container, it exerts a tiny force. Summing up thousands or millions of these tiny forces results in the gas pressure we observe.
In this way, particle collisions are the mechanisms that translate the energy of motion (kinetic energy) into force (pressure). Understanding this concept helps in grasping why heating a gas increases its pressure, as faster-moving particles mean more frequent and intense collisions, increasing the force exerted on container walls.