Ideal Gases

Question 1

Assumptions of ideal gas model

Answer 1

1) Molecules of gas are in a constant random motion.
2) Collisions between molecules are perfectly elastic.
3) The volume occupied by gas molecules is
negligible compared to the volume of the container they occupy.
4) There are no intermolecular forces between gas particles.
5) The kinetic energy of the gas is directly proportional to Kelvin temperature.

Question 2

Pressure and volume relationship

Answer 2

P=k/V (k is constant) k=pV
p1V1=p2V2

pressure is pascal - Pa
N/m^2, J/m^3

STP for gas is 273.15K and 100kPa

Question 3

Real gases

Answer 3

Deviate from behavior of ideal gas at
1) high pressure - There are more molecules in a reduced space. The volume of the molecules becomes a significant part of the volume of the gas. As molecules themselves can not be compressed, only the space between them, the relationship between pressure and volume is no longer inverse, so the gas is not considered to be an ideal gas.

2) low temperature - KE of gas molecules is reduced. As they collide with each other, intermolecular forces of attraction form and molecules may not rebound elastically

Question 4

Ideal gas condition

Answer 4

• ideal gas conditions keep molecules far apart and prevent interaction between them
• conditions for ideal gas are high temperature and low pressure
• at low pressure, there are very few molecules per unit volume in the container, so the space occupied by the molecules themselves is negligible.
• at high temp, the molecules are moving too fast to allow them to allow for intermolecular forces of attraction to form