Question

recall the postulates of kinetic-molecular theory. read the list and choose three statements that apply to the behavior of an ideal gas.

• gas particles occupy most of the space within a container
• gas particles have mass and volume
• gas particles behave like hard spheres
• gas particles are attracted to each other
• energy is lost when gas particles collide
• average kinetic energy of a collection of gas particles depends on the temperature
• gas particles travel randomly

Explanation:

Analyze the question prompt

The prompt asks to recall the postulates of kinetic-molecular theory and choose three statements that apply to the behavior of an ideal gas.

Evaluate each statement

• gas particles occupy most of the space within a container: Incorrect. Ideal gas particles are assumed to have negligible volume compared to the container volume.
• gas particles have mass and volume: Incorrect. While real gas particles have volume, ideal gas theory assumes the volume of individual particles is negligible (effectively zero).
• gas particles behave like hard spheres: Correct. Kinetic-molecular theory models ideal gas particles as hard, spherical objects.
• gas particles are attracted to each other: Incorrect. Ideal gas theory assumes there are no intermolecular attractive or repulsive forces between particles.
• energy is lost when gas particles collide: Incorrect. Collisions between ideal gas particles are assumed to be perfectly elastic, meaning no net kinetic energy is lost.
• average kinetic energy of a collection of gas particles depends on the temperature: Correct. The average kinetic energy is directly proportional to the absolute temperature (in Kelvin).
• gas particles travel randomly: Correct. Ideal gas particles are in constant, rapid, random straight-line motion.

Select the three correct statements

The three correct statements describing ideal gas behavior according to the kinetic-molecular theory are:

1. gas particles behave like hard spheres
2. average kinetic energy of a collection of gas particles depends on the temperature
3. gas particles travel randomly

Answer:

• gas particles occupy most of the space within a container
• gas particles have mass and volume
• gas particles behave like hard spheres (Correct answer)
• gas particles are attracted to each other
• energy is lost when gas particles collide
• average kinetic energy of a collection of gas particles depends on the temperature (Correct answer)
• gas particles travel randomly (Correct answer)