Question

a sample of gas is enclosed in a container of fixed volume. identify which of the statements are true. choose three correct answers:

• if the container is cooled, the gas particles will lose kinetic energy and temperature will decrease
• if the gas particles move more quickly, they will collide more frequently with the walls of the container and pressure will increase
• if the container is heated, the gas particles will lose kinetic energy and temperature will increase
• if the gas particles move more quickly, they will lose energy more rapidly and collide with the walls of the container less often, and pressure will decrease
• if the gas particles move more quickly, they will collide with the walls of the container more often and with more force, and pressure will increase

Explanation:

Analyze cooling effects

Using the Kinetic Molecular Theory knowledge point

$$ T \propto \text{KE}_{\text{avg}} $$

Cooling decreases average kinetic energy and temperature.

Analyze heating effects

Using the Kinetic Molecular Theory knowledge point

$$ T \propto \text{KE}_{\text{avg}} $$

Heating increases average kinetic energy and temperature, not decreases.

Analyze particle speed and collision frequency

Using the Kinetic Molecular Theory and Gas Laws knowledge points

$$ v_{\text{rms}} \propto \sqrt{T} $$

Faster particles collide more frequently with container walls, increasing pressure.

Analyze particle speed and collision force

Using the Kinetic Molecular Theory and Gas Laws knowledge points

$$ P = \frac{F}{A} \propto \text{collision frequency} \times \text{collision force} $$

Faster particles collide more frequently and with greater force, increasing pressure.

Answer:

• If the container is cooled, the gas particles will lose kinetic energy and temperature will decrease (Correct answer)
• If the gas particles move more quickly, they will collide more frequently with the walls of the container and pressure will increase. (Correct answer)
• If the container is heated, the gas particles will lose kinetic energy and temperature will increase
• If the gas particles move more quickly, they will lose energy more rapidly and collide with the walls of the container less often, and pressure will decrease
• If the gas particles move more quickly, they will collide with the walls of the container more often and with more force, and pressure will increase. (Correct answer)