Question

Which of the following correctly defines the principles of kinetic molecular theory?

Answer 1

Answer:

• Option a. There are no attactions between particles.

Explanation:

These are the main principles of kinetic molecular theory of gases:

1) Gases are formed by a huge number of particles (atoms or molecules) in constant, random motion.

This, along with the number four below, makes false the option d, that "When particles collide, they become motionless".

2) The particles (molecules or atoms) are very small and occupy a neglectible volume. Then, the space between particles is much larger than the size of  the particles (most of the volume of a gas is  empty space).

This makes false the option b, that "The space between the particles is the same as the size of the particles"

3) There is no force of attraction between gas particles or between the particles and the walls of the container.

This is precisely the same stated in the choice a. There are no attractions between particles. So, this is the correct principle.

4) The collisions between gas particles or with the walls of the vessel are perfectly elastic. This means that there is not loss or energy when due to collisions.

As stated above, this contradicts the choice d.

5) The average kinetic energy of a set of gas particles depends only on the temperature of the gas.

In fact, the kinetic energy is directly related with the temperaute: as the temperature increases, the kinetic energy increases.

Since, the kinetic energy is also proportional to the square of the speed, the higher the temperature the higher the speed. So, particles move faster when temperature increases.

In conclusion, this contradicts the option c, that particles move slower when temperature increases.