Ideal Gases: Intermolecular Forces & Kinetic Energy

[Misr]

http://pages.towson.edu/ladon/gases.html

2. Collisions between ideal Gases are "elastic". This means that no attractive or repulsive forces are involved during collisions. Also, the kinetic energy of the gas molecules remains constant since theses interparticle forces are lacking.

"Elastic" means that the energy of the particle before collision equals to the energy of the particle after collision.
How is this related to the presence or absence of intermolecular forces and

How is this related to kinetic energy?
Does the particles loses energy when it is attracted to another particle?if yes,then could you explain how?

 

[TaxOnFear]

"Elastic" means that the energy of the particle before collision equals to the energy of the particle after collision.

Think about it, if you have an attractive force, then the kinetic energy will be greater before the collision than after, therefore the energy before the collision ≠ the energy after the collision, likewise with a repulsive force.

Which also answers your second question.

 

[Misr]

Yes I know that and i already mentioned it in the first post but I can't just imagine why intermolecular forces makes molecules lose energy?
but I can imagine that when the molecule rebounces , the other molecule attracts it so decreasing its kinetic energy and its speed.Is that okay?
how about the repulsive forces?

 

[Misr]

hello there?what's wrong with my post

 

[pmacias]

The concept of "elastic" collisions in ideal gases is closely related to the absence of intermolecular forces and the constant kinetic energy of gas molecules. In an ideal gas, the particles are assumed to be point masses with no volume and no intermolecular forces acting between them. This means that when two gas particles collide, they do not exert any attractive or repulsive forces on each other, resulting in an "elastic" collision where the total kinetic energy of the particles remains constant.

In contrast, in real gases, intermolecular forces do exist and can affect the motion of gas particles. When two gas particles are attracted to each other, they will lose some of their kinetic energy as they move closer together. This loss of kinetic energy is known as potential energy, and it is converted into heat energy, resulting in a decrease in the overall kinetic energy of the particles. This is why real gases do not exhibit "elastic" collisions and the total kinetic energy of the particles is not constant.

In summary, the absence of intermolecular forces in ideal gases allows for "elastic" collisions and the constant kinetic energy of particles, while the presence of intermolecular forces in real gases leads to inelastic collisions and a decrease in the overall kinetic energy of particles.