In gas law calculations, air is often considered to be a single gas with a molar mass of 29 g/mole. On this basis, calculate the density of air, in g/L, on a hot summer day when the temperature is 41oC and the atmospheric pressure is 0.91 atm.

Question

In gas law calculations, air is often considered to be a single gas with a molar mass of 29 g/mole.  On this basis, calculate the density of air, in g/L, on a hot summer day when the temperature is 41oC and the atmospheric pressure is 0.91 atm.

oobleck · Answer

If there were one mole of air, it would occupy 28.3L under those conditions. so, you must have 28.3/22.4 = 1.26 moles That would be 1.26*29g/28.3L = 1.29 g/L