Question

According to kinetic theory of gases, which one of the following statements is wrong?

• A. All the molecules of a gas are identical.
• B. Collisions between the molecules of a gas and that of the molecules with the walls of the container are perfectly elastic.
• C. The molecules do not exert appreciable force on one another except during collision.
• D. The pressure exerted by a gas is due to the collision between the molecules of the gas.

Hint:

Logic Tip: While molecules do collide with each other, it is the momentum transfer to the container walls that creates measurable pressure.

Answer 1

The Correct Option is D

Concept: According to the kinetic theory of gases, the macroscopic properties of gases arise from the motion of a large number of microscopic particles.
Step 1: Correct postulates of kinetic theory

• Gas molecules are identical point masses with negligible volume.
• They are in constant random motion.
• Collisions between molecules and with container walls are perfectly elastic.
• There are no intermolecular forces except during collisions.

Step 2: Origin of pressure Pressure of a gas is due to the continuous collisions of gas molecules with the walls of the container. These collisions transfer momentum, resulting in force per unit area (pressure).
Step 3: Identify the incorrect statement Any statement claiming that pressure is caused solely by collisions \textit{between gas molecules} is incorrect. Conclusion: \[ \boxed{\text{Pressure is due to collisions with container walls, not just intermolecular collisions \]