Question 1 - Gas Laws

Question 1

What is an ideal gas?

Answer 1

An ideal gas has particles of a negligible size, all interactions are fully elastic/ has no IMFs.
Obeys PV = nRT and Charles’/Boyle’s law.

Question 2

Explain how the ideal gas law is consistent with the experimentally determined Boyle’s and Charles’ law.

Answer 2

If T and amount of gas are held constant we have Boyle’s law.
If P and amount of gas are held constant we have Charles’ law.

Question 3

What are the key assumptions for an ideal gas?

Answer 3

Particles are in constant motion
There are no significant interactions between molecules and the inside surface and their container apart from collisions (all collisions are perfectly elastic)
Molecules take up negligible volume.

Question 4

What is a real gas, how does it differ from an ideal gas?

Answer 4

Differs from ideal gas equation and Charles’/Boyle’s law in high density (or low T, low V, high P) situations because the volume is non negligible and therefore has significant IMFs.

Question 5

Name an equation that can be used to relate the variables in a real gas.

Answer 5

Van der Waals equation
(P+n2a/V2)(V-nb) = nRT
a = adjustment factor for the presence of forces
b = adjustment factor for the volume
Constants a and b are experimentally determined for each gas

Question 6

What is the R and what are its units?

Answer 6

The universal gas constant R = 8.314JK-1mol-1