You take 1 gallon of water (about 3785 grams) and use electrolysis to convert it to oxygen and hydrogen gas. (3785 grams of water is about 211 moles of of water.) Based on the mole-to-mole ratio you collect 211 moles of H2 gas for use in your hydrogen powered car. How much volume (in liters) does the gas take up at room temperature?
2 H20 m) -> 2 H2(g) + O2(g) temperature = 300 Kelvin pressure = 1 atm n = 211 moles R = 0.0821 Liter x atm/ (K x mole)
Follow up to the previous question: You decide to store the H2 gas in your current gas tank which unfortunately only holds 50 liters. At approximately what pressure would you need to store the gas (assuming it is at room temperature) for all of it to fit in your gas tank?
Use Boyle's Law: P1V1 = P2V2 (Note: Your gas tank would not be able to hold this pressure.)
a. 1 atm
b. 10 atm
c. 100 atm
d. 1000 atm