Question

How many grams of water form when 1.24 l of gas h2 at stp completely reacts with o2?

Answer 1

Balanced reaction for formation of water is ;
2H2 + O2 —> 2H2O
Stoichiometry of H2 to H20 is 2:2
1 mol of any gas occupies a volume of 22.4 L
Therefore it 22.4 L contains 1 mole
Then 1.24 L has -1/22.4 x 1.24 = 0.055 mol
Number of water moles formed = 0.055 mol
Therefore mass of water formed = 0.055 mol x 18 g/mol = 0.99 g of water is formed