When a fresh breath of air is drawn into the lungs, it is heated by your body. Let’s assume it reaches thermal equilibrium with your body temperature of 37°C. Given the temperature, pressure, and the average molar mass of air, you could easily calculate that your breath of 0.48 L corresponds to 0.51 g of air. The specific heat of air is 1.0 J/g•°C.

I. Given that the temperature outside is 21°C, how much heat is required to take the air in your 0.48 L breath from 21°C to 37°C?

II. The heat calculated in the previous question is lost every time you exhale. Assuming 15 breaths per minute, how much heat would be lost in one day by exhaling? Furthermore, assuming a daily energy intake of 8400 kJ (corresponding to 2000 food Calories), what percent of your daily energy intake is lost as heat due to exhaling during a 24 hour period?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Thermal Equilibrium concept. You can view video lessons to learn Thermal Equilibrium. Or if you need more Thermal Equilibrium practice, you can also practice Thermal Equilibrium practice problems.

What is the difficulty of this problem?

Our tutors rated the difficulty of*When a fresh breath of air is drawn into the lungs, it is he...*as high difficulty.

How long does this problem take to solve?

Our expert Chemistry tutor, Ellen took 3 minutes and 57 seconds to solve this problem. You can follow their steps in the video explanation above.