# What is the volume composition of this gas mixture?

## Determine the composition of the gas mixture(in the volume percentages!!!) if T=298K, p=101 325Pa, density=1,126kg/m3. The gas mixture is made of nitrogen and oxygen. I think it should be done as a task from ideal gases, there were similar examples in the workbook.

Jan 4, 2017

Determine the composition of the gas mixture(in the volume percentages!!!) if T=298K, p=101 325Pa, density=1,126kg/m3. The gas mixture is made of nitrogen and oxygen.

$d = 1.126 \text{kg/"m^3=(1.126xx10^3)/10^3"g/"dm^3=1.126"g/} L$

$P = 101325 P a = 1 a t m$

$T = 298 K$

$R = 0.082 L a t m {K}^{-} 1 m o {l}^{-} 1$

By equation of state of ideal gas we have

$P = \frac{d}{M} R T$ ,where M represents average molar mass of the mixture.

$M = \frac{\mathrm{dR} T}{P} = \frac{1.126 \times 0.082 \times 298}{1} g m o {l}^{-} 1 \approx 27.515 \text{g/mol}$

If the $x$ represnts the percentage of nitrogen by volume in the given mixture,then the percentage of number of moles of nitrogen in the mixture will also be $x$.

Hence average molar mass becomes

$M = \frac{28 \cdot x + 32 \cdot \left(100 - x\right)}{100} = 27.515$

$\implies 3200 - 4 x = 2751.5$

=>x=(3200-2751.5)/4=112.125%

This is impossible