Question

Under what conditions can a gas be considered ideal? Give three conditions.

Discuss whether or not the ideal gas law is valid at all temperatures (absolute zero to extremely hot).

Discuss whether or not the ideal gas law is valid at all pressures (vacuum to high pressure).

Answer 1

Ideal gas is that which obeys Gas Laws at all temperature and pressure but real gases do not obey gas laws at all temperature and pressure.
Real gases only obey Gas Laws at high temperature and low pressure. Because at these conditions the gas molecules have much empty spaces between them and the actual volume can be negligible. And also the intermolecular forces at these conditions can not be felt by molecules because they are so far apart from each other. That's why intermolecular forces are also negligible and the potential energy due to intermolecular forces becomes less significant compared with the particles' kinetic energy, and the size of the molecules becomes less significant compared to the empty space between them.