Question

Help with Physics Homework:

The total mass of the hydrogen gas in the Hindenburg zeppelin was 18,000 kg. 
What volume did the hydrogen occupy?  (Assume that the temperature of the hydrogen was 0°C and that it was at a pressure of 1 atm.)

Answer 1

Hello
We will use the state equation for an ideal gas to determine the volume that the Hydrogen occupied. The equation is
pV = nRT; where p is pressure in pascals, V is volume in meters cubed, n is the number of moles present, R is the gas constant (value 8.314 J/K*mol) and T is the absolute temperature in Kelvins.
First we convert 1 atm to Pascals, which is 101325 Pascals
Next, the temperature is converted to Kelvin by adding 273; so 273K
Finally, we must compute n by dividing the mass of the Hydrogen gas by its Molecular mass of 2. We obtain 9000 moles of Hydrogen gas. Substituting into the equation after rearranging for V:
V = (9000 * 8.314 * 273)/101325
Volume of Hydrogen present is 201.6 meters cubed.

Answer 2

Formula is:
P V = n R T
n = m / M
P * V = m / M * R * T
P = 1 atm = 101,325 Pa ; m = 18,000 kg; M = 0,002 kg/mole;
R = 8.314 J /mole K; T = 0° C = 273 K;
101,325 Pa * V = 18,000 kg / 0.002 kg/mole * 8.314 J/mole K * 273 K
V = ( 9,000,000 * 8.314 * 273 ): 101,325
V = 201,603.7 m³