Calculate the mass of air in the sphere using the State 1 pressure and temperature.

Question

Temperature = 23.25 C

Pressure = 100 KPa

The Volume = 5.352 x 10^-4 m^3

Calculate the mass of air in the sphere using the State 1 pressure and temperature.

Answer 1

1) Convert temperature to absolute: 23.25 + 273.15 = 296.4 K

2) Look up R in appropriate units. R = 0.00831446 m³•KPa/(K•mol)

3) Use the ideal gas law PV = nRT to calculate the number of moles of air:

PV = nRT

n = (PV)/(RT)

n = (100)(5.352 x 10^-4)/(0.00831446•296.4)

n = 0.021717 moles

4) Look up (or calculate) the molar mass of air: 28.9647 g/mol

5) Multiply the number of moles by the molar mass to get the mass of air: (0.021717)(28.9647) = 0.629 grams