The balanced chemical equation for the formation of water is:
2H2(g)+O2(g)→2H2O(g)
First, we calculate the number of moles of each reactant:
Molar mass of H2=2 g/mol.
Moles of H2=2 g/mol10 g=5 moles.
Molar mass of O2=32 g/mol.
Moles of O2=32 g/mol64 g=2 moles.
Now, we determine the limiting reagent. From the balanced equation, 2 moles of H2 react with 1 mole of O2.
Thus, for 2 moles of O2, the required moles of H2 would be 2×2=4 moles.
Since 5 moles of H2 are present (which is more than the required 4 moles), O2 is the limiting reagent and H2 is in excess.
The amount of product formed depends completely on the limiting reagent (O2).
According to the stoichiometry, 1 mole of O2 produces 2 moles of H2O.
Therefore, 2 moles of O2 will produce 2×2=4 moles of H2O.