Question

Dry air (0% humidity) is approximately 78% N2, 21% O2, and 1% Ar by moles. Calculate the molar mass and density of dry air at 0 °C and 1.0 atm. Assume ideal behavior and use two significant figures in your answers.

Answer 1

Step-by-step explanation:

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Answer 2

The molar mass of dry air = 28.94

Density = 1.29

Step-by-step explanation:

Mm of N2= 28, Mm of O2= 32, Mm Ar= 39.9

78% of N2 by mole give = 0.78×28= 21.84

21% of O2 by mole give = 0.21× 32= 6.72

1% of At by mole give = 0.01× 39= 0.39

Hence overall molecular weight of air = 21.84+6.72+0.39= 28.94

Density = m/ v,

1- mole of air occupy 22.4dm^3 volume

Density= 28.94/22.4= 1.29