Final answer:
The chemical that makes the air cold in an automobile air conditioner is refrigerant, which undergoes a phase change from a gas to a liquid and back to a gas again in a continuous cycle. This phase change process absorbs heat from the air, making it colder. The commonly used refrigerant in automobile air conditioners is dichlorodifluoromethane, also known as R-12 or Freon-12.
Step-by-step explanation:
The chemical that makes the air cold in an automobile air conditioner is refrigerant.
Refrigerants are substances that undergo a phase change from a gas to a liquid and back to a gas again in a continuous cycle. This phase change process absorbs heat from the air, making it colder. In automobile air conditioners, a commonly used refrigerant is dichlorodifluoromethane, also known as R-12 or Freon-12.
When the refrigerant is compressed, it becomes a hot, high-pressure gas. This gas then flows through a series of coils located in the air conditioner. As the hot gas passes through the coils, it releases heat to the surroundings and cools down, eventually turning into a liquid. The liquid refrigerant then flows through an expansion valve, where its pressure is reduced. This causes it to evaporate and turn back into a gas. During this evaporation process, the refrigerant absorbs heat from the air, making it cool. The cool air is then blown into the car's interior, providing a refreshing breeze.