What is the maximum mass of H2O that can be produced by combining 90.8 g of each reactant

1 answer

Write the equation and balance it.
mols H2 = grams/molar mass
mols O2 = grams/molar mass

Convert mols H2 to mols product.
Do the same for O2.
The smaller number of mols wins; that will be the mols H2O produced. Then mol x molar mass H2O = grams H2O.