Why Do Compressed Air Cans Get Cold?

Compressed air cans, often used for cleaning, get cold due to the phase change of 1,1-difluoroethane from liquid to gas. This process absorbs energy, cooling the can. Unlike normal gas expansion, the liquid inside the can maintains pressure, allowing consistent spray. The cooling effect is similar to a pressure cooker, where releasing pressure allows more liquid to boil, cooling the remaining contents. Safety warnings advise against shaking or inverting the can, as this can cause liquid to spray out, rapidly cooling surfaces it contacts.

What happens to the temperature of the gas when it expands from a compressed air can?

Explain why shaking a can of compressed air is not recommended.

Describe the role of 1,1-difluoroethane in a can of compressed air.

What is the significance of the pressure inside a can of compressed air?

How does the cooling effect in a can of compressed air compare to the evaporation of sweat?