Need chem help What volume is occupied by 1.00 kg of helium at 5.00◦C at a pressure of 735 Torr?

3 Answers

• Using the Ideal Gas Equation

  PV = nRT

  V = nRT/P

  Where

  n = moles(He) = 1000g / 4 = 250 moles

  R = Gas Constant 8.413.

  T = temperature in Kelvvin K (5 + 273 = 278

  P = pressure in Pascals(Pa) 98,19213 Pa

  Hence

  V = 250 x 8.314 x 278 / 98192

  V = 5.88 m^3 ( NOT dm^3 nor cm^3, but cubic metres).

• Ideal gas equation problem ….

  PV = nRT ……………. ideal gas equation

  PV = mRT / M ……… n=m/M … m=mass, M=molar mass

  V = mRT / (PM) ……. solve for V

  V = 1000g x 62.36Ltorr/molK x 278.15K / 735 torr / 4.00 g/mol

  V = 5.90×10^3 L ……. to three significant digits

• 1Kg  ==  1000/4  =  250 moles

  V = nRT/P  =  (250)(62.4)(278)/735

   V = 5900 L