The dirigible Hindenburg had 3.7E6 m3 of hydrogen in its gas bags at 1.1 atm and 7°C. What was the weight of the hydrogen in pounds?

Assuming that the gas is ideal, we can use the ideal gas equation PV=nRT to calculate for the number of moles. Then, multiply the molar mass of the gas to obtain the mass. We do as follows:

PV = nRT

n = PV / RT

n = 1.1 atm (3.7x10^9 L) / 0.08205 L-atm/mol-K (280.15) = 177061931.3 mol H2

Mass = (177061931.3 mol H2) 18.02 g/mol (1 kg / 1000g) (2.2 lb / 1 kg) = 7019443.21 lb H2