What is the weight of air in a room 20ft x 30ft x 10ft?

Answer 1

Air density decreases with increasing altitude, as does air pressure. It also changes with variances in temperature or humidity. At sea level and at 15 °C according to ISA (International Standard Atmosphere), air has a density of approximately 1.225 kg/m3. The addition of water vapor to air (making the air humid) reduces the density of the air, which may at first appear counter-intuitive. This occurs because the molecular mass of water (18 g/mol) is less than the molecular mass of dry air.

To calculate the density of air as a function of altitude, one requires additional parameters. They are listed below, along with their values according to the International Standard Atmosphere, using the universal gas constant instead of the specific one:

· sea level standard atmospheric pressure p0 = 101.325 kPa

· sea level standard temperature T0 = 288.15 K

· Earth-surface gravitational acceleration g = 9.80665 m/s2.

· temperature lapse rate L = 0.0065 K/m

· ideal (universal) gas constant R = 8.31447 J/(mol·K)

· molar mass of dry air M = 0.0289644 kg/mol

To calculate the weight of air in a room you need to know more than the dimensions of the room. So the 'correct' answer is impossible to know. Either that or the person who asked the question didn't understand the question they were asking!