Kinetic Molecular Theory
The
ideal gas law doesn't work for ALL gases, only the ones we call
“ideal”. What makes something an ideal gas? Different gases
have different degrees of “ideality” depending on whether or not
the molecules follow certain assumptions. These assumptions are
collectively known as kinetic
molecular theory
Gases behave very ideally at high temperature and low pressure. High temperature means the molecules are moving around faster and have less chance of sticking together. Lower pressure means that the molecules are far apart from each other and won't interact as much.
Gases behave very non-ideally at low temperature and high pressure since slow-moving, closely-packed molecules are more likely to interact with each other.
When a gas behaves very non-ideally, we can't use the ideal gas law anymore...we have to use something called the van der Waals' equation
- the
molecules move completely randomly
- the
molecules have NO volume
- the
molecules do not interact with each other
- no
energy is lost in collisions between molecules
- the
average kinetic energy of the molecules is proportional to the
temperature of the gas (in K)
Gases behave very ideally at high temperature and low pressure. High temperature means the molecules are moving around faster and have less chance of sticking together. Lower pressure means that the molecules are far apart from each other and won't interact as much.
Gases behave very non-ideally at low temperature and high pressure since slow-moving, closely-packed molecules are more likely to interact with each other.
When a gas behaves very non-ideally, we can't use the ideal gas law anymore...we have to use something called the van der Waals' equation
