Which of the following statements is/are true for gas molecules according to the Kinetic Molecular Theory?


I. Increasing the amount of gas molecules increases the pressure by increasing the force of the collisions.
II. Decreasing the temperature of a gas decreases the pressure by increasing the force of the collisions.
III. Decreasing the volume of a gas increases pressure by increasing the frequency of the collisions.

• A. I only
• B. II only
• C. III only
• D. I and II
• E. II and III

Answer: (C)

Verified step by step guidance

1. Understand the Kinetic Molecular Theory: This theory explains the behavior of gas molecules, stating that gas pressure is due to collisions of molecules with the walls of the container.
2. Analyze statement I: Increasing the amount of gas molecules increases the pressure because more molecules result in more collisions with the container walls, thus increasing the force exerted.
3. Analyze statement II: Decreasing the temperature of a gas typically decreases the pressure because the molecules move slower, resulting in less frequent and less forceful collisions, contrary to the statement.
4. Analyze statement III: Decreasing the volume of a gas increases pressure because the molecules have less space to move, leading to more frequent collisions with the container walls.
5. Evaluate the statements: Based on the analysis, statement III is true according to the Kinetic Molecular Theory, while statement I is partially true and statement II is false.