a tank contains helium molar mass 4kgkmol at 1MPa and 20 deg

a tank contains helium (molar mass= 4kg/kmol) at 1MPa and 20 degrees C.

a) if the volume of the tank is 4m^3, determine the mass of the helium in the tank

b) if the volume of the tank is 4m^3 determine the mole of helium in the tank

Pressure = 1 MPa

Temperature = 293.15 K

Molar Mass = 4 kg / kmol

Volume of Tank = 4 m³

For ideal gas ,

PV =nRT

n = PV/RT

= (1 MPa x 4 m³ ) / (8.314 J/mol K x 293.15 K )

= 1641.2 moles

So, mass of helium = 1.6412 kmoles x 4 kg / kmol

= 6.5648 kg

Moles of Helium = 1.6412 kmoles