Ideal Gas Law

pV = n R T

  • p  pressure in  Pa   
  • V  volume in m3
  • n  number of moles
  • R  gas constant   R = 8.3145 Jmol-1K-1
  • T  Kelvin temperature  in K

Example

In a tank of 200 ℓ is helium. The pressure in the tank is 30 bar and the temperature  is 20 oC.

Calculate the mass of helium.

p V = n R T

(30 x 105)( 200 x 10-3) = n (8.31) (293) 

n = ((30 x105)( 200 x 10-3)) / (8.31 x 293) = 246 mol

mass per mol of helium is 4.0 g mol-1

mass of helium : 246 x 4 = 985.7 g = 9.9 x 102

Enable Notifications    OK No thanks