Question

How would you prove that the air you breathe out is warmer?

Answer 1

Hint: Air is a mixture of gases. It is one of the most important components that make life on earth possible. The air that we breathe is a homogeneous mixture. Air contains oxygen, nitrogen, carbon dioxide, argon, and other elements in small quantities.

Complete answer:
Air is a homogenous mixture of oxygen, nitrogen, carbon dioxide, argon, and other elements in small quantities. A homogenous mixture is something that has the same proportion of its components.
Now discussing exhaled air, the air we exhale is known to be warmer and cleaner from the inhaled air. It is said that air in our lungs becomes warm by the body heat. Thus, causing a difference in temperature between exhaled and inhaled air. When we inhale, the air is taken up by the lungs and provides oxygen to be pumped around by our blood. Therefore, the oxygen is mostly used up and the by-product carbon dioxide with some other gases is exhaled.
This can be proved by a simple experiment where you keep your hand in front of your face and breathe. You will feel warm air coming out of your nose. You can also try standing close to the mirror and blow on the surface of it. You will notice droplets of water which proves that exhaled air is warmer than the surrounding environment. The condensation air takes place and hence the droplets are formed.

Note: It is also said that exhaled air is cleaner than the inhaled air as it is filtered out by our lungs. The amount of a carbon dioxide is also higher in exhaled air when compared to inhaled air. Thermistors and thermocouples are devices used to determine the warmth of air.