In modern integrated gasification combined cycle (igcc) coal-fed power plants, oxygen is produced via cryogenic separation of air and is fed to the igcc plant along with coal. the separation of oxygen from air is expensive, what reason(s) can you give for doing this?

How does the motion of particles in a gas change as the gas cools

Light waves travel than sound waves.

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?