Question

Which of the following assumptions is incorrect according to gases?
A. Particles of a gas move in all possible directions in straight lines.
B. All the particles, at any particular time, have the same speed and same kinetic energy.
C. There is no force of attraction between the particles of a gas at ordinary temperature and pressure.
D. The actual volume of the gas is negligible in comparison to the empty space between them.

Answer 1

Hint: The speed of the gas particles which deposited during the movement depends upon their masses and also the temperature. Thus, all the particles cannot have the same speed even at any particular time.

Complete answer:
The kinetic theory of gases the gas particles move randomly in all directions. The movement of the particles is constant. These particles of gases move at different speeds.
Particles of gases usually move in straight lines and the change their direction after collision. These collisions can be either with the other particles or with the walls of the container in which the gas is stored.
The gas particles possess kinetic energy as they move constantly and all the objects which are in motion have kinetic energy. The kinetic energy is calculated using mass and speed of particles.
The speed of all the particles in a container or a gas sample is not the same because heavier particles move slowly and the lighter ones move fast. Thus, the speed varies with the particles.
The force of attraction between the gas particles is not so strong and that is the reason why they move independent of each other.
This is due to the fact that the attractive force between gas particles is much lesser than their kinetic energy due to which the distance between them is large and the force of attraction, thus, less.
The distance between the gas particles is much greater than their sizes. So, there is a lot of empty space in terms of gas volume and the volume of gas molecules becomes negligible.
The correct answer is (B).

Note: The kinetic energy of all gases is the same at a particular temperature because the Absolute Temperature of gas is directly proportional to the kinetic energy of its particles.