SECTION REVIEW
1. Use the kinetic-molecular theory to explain each
of the following properties of gases: expansion,
fluidity, low density, compressibility, and diffusion.
2. Describe the conditions under which a real gas is
most likely to behave ideally
3. Which of the following gases would you expect to
deviate significantly from ideal behavior: He. O
Hz, H, O, N2, HCI, or NH,?
4. How does the kinetic-molecular theory explain the
pressure exerted by gases?
5. What happens to gas partides when a gas is
compressed?
6. What happens to gas partides when a gas is
heated?

2. High tempertaure and low pressure

3. HCL,NH3,H20

4. higher collisions ieThe greater the number of gas molecules, higher will be the collision rate and hence the greater the pressure.

Explanation:

Expansion:

1. Suppose gas particles are moving in a linear fashion but if they collide with some thing they will fil that. This explains expansion theory of gases.

Fluidity: The gas molecules are in dependent of each other and have low density, they are in constant motion hence have fluidity.

low density: The gas molecules are far apart as compared to solid and liquid hence have low density.

compressibility:  Due to the large distance between the gas molecules they collide with each other and vessel wall and when the space is constricted they start moving faster. They are elastic in nature.

Diffusion: Yes, because when gas is mixed it starts moving in the mixture randomly.

2. The molecules in real gas are at large distance. The high temperature and low pressure real gas would behave ideally. Because increase temperature would cause higher movement of gas particles.

3. HCL, NH3 and H2O are polar gases they will have relatively different attractive forces between them.

4. The greater the number of gas molecules, higher will be the collision rate and hence the greater the pressure.

5. The gas particles get closer, enough pressure not provided. It increases the kinetic energy as heat is produced due to compaction of molecules. The particles would not move and will become liquid causing volume to increase.

6. The gas molecules start moving rapidly, move farther apart .Volume and pressure also increases.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.