The Gaseous State Flashcards
(7 cards)
What are the 3 properties of Gases?
Low density
Particles don’t have strong attraction
Particles move randomly -> diffusion
Describe an ideal gas.
For a gas to be classified as “ideal”, we must make the following assumptions:
- The gas particles have negligible volume
- The gas particles are equally sized and do not have intermolecular forces of attraction or repulsion
- The gas particles move randomly and continuously
- The gas particles have perfect elastic collisions with no energy loss
What are the properties of ideal gases?
The absolute temperature in Kelvin is directly proportional to the average kinetic energy of the particles
Pressure is caused by particles hitting the walls of the container
Define Boyle’s Law.
The product of pressure and volume is constant at a given mass and constant temperature.
pV = constant
Pressure is inversely proportional to volume.
Define Charles’ Law.
The ratio of absolute temperature to volume is equal to a constant for a specific amount of gas at constant pressure
T/V = constant
Temperature is directly proportional to volume.
Describe the Ideal Gas Law.
pV = nRT
p - pressure of gas (Pa)
V - volume of container (m3)
n - moles
R - gas constant: 8.31 J.K-1.mol-1
T - absolute temperature (K)
Standard conditions:
298K
100 kPa
Describe non-ideal gases.
Assumptions for ideal gases do not apply to real(non-ideal) gases.
Real gases behave less like ideal gases are:
1. Very high pressure
- Particles move closer together therefore the forces of attraction have a greater impact.
2. Very low temperature
- Particles have less kinetic energy and don’t move around as freely.
In addition, the particles take up less space when they are cooled at high pressure. Hydrogen and Helium deviate the least from ideal gas behaviour.
Real gases behave most like ideal gases are:
- High temperature
- Low pressure
- Low molecular mass (Mr)
