The question appears to have a slight error, as Trichlorofluoromethane is a synthetic compound and not obtained from air. Assuming the question intends to ask about how Nitrogen is obtained from air

The question appears to have a slight error, as Trichlorofluoromethane is a synthetic compound and not obtained from air. Assuming the question intends to ask about how Nitrogen is obtained from air on a large scale, the process is fractional distillation of liquid air.

Here's the description of the process:

a) Describe the process by which Nitrogen is obtained from air on a large scale:

1. Filtration: Air is first filtered to remove dust particles.
2. Cooling and Compression: The filtered air is then compressed and cooled to remove water vapor (which condenses) and carbon dioxide (which solidifies).
3. Liquefaction: The remaining air, primarily nitrogen and oxygen, is further cooled to very low temperatures (around $-200^\circ\text{C}$) until it liquefies. This is often achieved through repeated compression and expansion cycles.
4. Fractional Distillation: The liquid air is then fed into a fractionating column. As the liquid air slowly warms up, the components separate based on their different boiling points. Nitrogen, with a boiling point of $-196^\circ\text{C}$, boils off first and is collected as a gas at the top of the column. Oxygen (boiling point $-183^\circ\text{C}$) and Argon (boiling point $-186^\circ\text{C}$) are collected separately at different levels.