Question

People often think of humid air as "heavy." Compare the densities of air with 0% relative humidity and 100% relative humidity when both are at 1 atm and 30°C. Assume that the dry air is an ideal gas composed of molecules with a molar mass of 29.0 g/mol and the moist air is the same gas mixed with water vapor.

Answer 1

The density of air with 0% relative humidity and 100% relative humidity at 1 atm and 30°C can be compared by considering the density of dry air and the density of water vapor. The addition of water vapor affects the density of the air, so by comparing the two densities, we can determine the difference in density between air with 0% and 100% relative humidity.

Step-by-step explanation:

Humidity is often associated with the feeling of air being heavy. The density of air with 0% relative humidity and 100% relative humidity can be compared at 1 atm and 30°C. Dry air is an ideal gas composed of molecules with a molar mass of 29.0 g/mol. When the air is dry, its density can be calculated using the ideal gas law. However, when the air is humid, it becomes a mixture of dry air and water vapor. The addition of water vapor affects the density of the air. To calculate the density of moist air, the density of dry air and the density of water vapor must be considered, along with their respective mole fractions. By comparing the two densities, we can deduce the difference in density between air with 0% relative humidity and 100% relative humidity.