Stoichiometry of Reactions: Gram/Mole

Question

According to the following reaction, how many moles of hydrogen gas will be formed upon the complete reaction of 27.2 grams of water ?

water(l)  hydrogen(g) + oxygen(g)

Answer 1

2H₂O(l) ==> 2H₂(g) + O₂(g) ... balanced equation

Use stoichiometry and dimensional analysis...

27.2 g H₂O x 1 mol H₂O/18 g x 2 mol H₂ / 2 mol H₂O = 1.51 mols H₂