Question

Plz solve this fast

If the components of the air are N2, 78%; O2, 21%; Ar, 0.9% and CO2, 0.1% by volume, what would be the molecular mass of air?​

Answer 1

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\ ⟹ Given Compositions N2, 78%; O2, 21%; Ar, 0.9% and CO2, 0.1% by volume.

\ ⟹ We need to follow Avagadro Principle.

\ ⟹ The molar ratios are also the volume ratios for the gases that is Avogadro’s principle.

\ ⟹ 1 Avagadro Number = 6.023×10^23 particles or sub-units

\ ⟹ Molecular mass of air by calculations ----

\ ⟹ = (78×28 + 21×32 + 0.9×40 + 0.1×44)/(78 + 21 + 0.9 + 0.1)

\ ⟹ Furthur solving ,

\ ⟹ = 28.964.

Answer 2

Plug in the mol weights of the compounds in

9.78×14(N2)+0.21×16(O2)+0.009×40(Ar) +0.001×(12+16 ×2)(co2)

=>136.92 + 3.36 + 0.36 + 0.056

=> 140.696 (molecular mass of the air)