P = 100.0 kPa
V = 1.1 kL = 1100 L
T = 20°C = 293 K
R = 8.314 kPa L mo-1 K-1
The decomposition reaction of water:
2H2O → 2H2 + O2
Ideal Gas Law can be used.
Ideal Gas Law can be expressed as: PV=nRT
To find the moles of H2, solve the equation for n:
n = PV/RT
Moles of H2 = n(H2) = (100.0 kPa × 1100 L) / (8.314 kPa L mol-1 K-1 × 293 K) = 45.156 mol
Moles of H2 = Mass of H2 / Molar mass of H2
The molar mass of H2 is 2.016 g/mol.
Finally, the mass of H2 is:
m(H2) = n(H2) × M(H2) = (45.156 mol) × (2.016 g/mol) = 91.034 g = 91 g
The mass of H2 is 91.0 g
Answer: 91 g is the mass of hydrogen required.