Question

Which one of the following is not an assumption of kinetic theory of gases?

• A. The volume occupied by the molecules of the gas is negligible.
• B. The force of attraction between the molecules is negligible.
• C. The collision between the molecules are elastic.
• D. All molecules have same speed.

Answer 1

The correct option is D All molecules have same speed.

According to postulates of KTG :
$1$. Gas contains large number of molecules which are identical and the volume occupied by the molecules is negligible compared to the volume of container.
$2$. The molecules are in continuous random motion. This random motion is also known as Brownian motion.
$3$. Collisions made by the molecules with the walls of container are perfectly elastic.
$4$. Effect of gravity on the motion of the molecules is negligible.
Hence option (d) is incorrect