posted by Anonymous .
In the explosion of a hydrogen-filled balloon, 0.80g of hydrogen reacted with 6.4g of oxygen. How many grams of water vapor are formed? (Water vapor is the only product.)
Express your answer using two significant figures.
This is a limiting reagent problem(except both are limiting reagent. :-).
2H2 + O2 ==> 2H2O
Convert 0.80g to mols. mol = grams/molar mass.
Convert 6.4 g O2 to mols. Same process.
Using the coefficient in the balanced equation, convert mols H2 to mols H2O.
Do the same for mols O2 to mols H2O.
Since mols H2O are the same for both reactants there is no limiting reagent and both reagent will be used completely.
Then grams H2O = mols of either x molar mass of that reactant. You can do each of them and show that grams H2O is the same no matter which is used.