A pressure vessel that has a volume of 10m3 is used to store high-pressure air for operating a supersonic wind tunnel. If the air pressure and temperature inside the vessel are 20 atm and 300K, respectively: What is the mass of air stored in the vessel

Respuesta :

Answer:

The mass of air stored in the vessel is 235.34 kilograms.

Explanation:

Let supossed that air inside pressure vessel is an ideal gas, The density of the air ([tex]\rho[/tex]), measured in kilograms per cubic meter, is defined by following equation:

[tex]\rho = \frac{P\cdot M}{R_{u}\cdot T}[/tex] (1)

Where:

[tex]P[/tex] - Pressure, measured in kilopascals.

[tex]M[/tex] - Molar mass, measured in kilomoles per kilogram.

[tex]R_{u}[/tex] - Ideal gas constant, measured in kilopascal-cubic meters per kilomole-Kelvin.

[tex]T[/tex] - Temperature, measured in Kelvin.

If we know that [tex]P = 2026.5\,kPa[/tex], [tex]M = 28.965\,\frac{kg}{kmol}[/tex], [tex]R_{u} = 8.314\,\frac{kPa\cdot m^{2}}{kmol\cdot K}[/tex] and [tex]T = 300\,K[/tex], then the density of air is:

[tex]\rho = \frac{(2026.5\,kPa)\cdot \left(28.965\,\frac{kg}{kmol} \right)}{\left(8.314\,\frac{kPa\cdot m^{2}}{kmol\cdot K} \right)\cdot (300\,K)}[/tex]

[tex]\rho = 23.534\,\frac{kg}{m^{3}}[/tex]

The mass of air stored in the vessel is derived from definition of density. That is:

[tex]m = \rho \cdot V[/tex] (2)

Where [tex]m[/tex] is the mass, measured in kilograms.

If we know that [tex]\rho = 23.534\,\frac{kg}{m^{3}}[/tex] and [tex]V = 10\,m^{3}[/tex], then the mass of air stored in the vessel is:

[tex]m = \left(23.534\,\frac{kg}{m^{3}} \right)\cdot (10\,m^{3})[/tex]

[tex]m = 235.34\,kg[/tex]

The mass of air stored in the vessel is 235.34 kilograms.