how many moles?

Question

For the reaction, calculate how many moles of the product form when 2.15 mol of O2 completely reacts. Assume that there is more than enough of the other reactant. 2H2(g)+O2(g)→2H2O(l) please help?

Answer 1

First write a balance equation
2H2(g)+O2(g)→2H2O(l)

Next, note the mole ratio of reactants to products, taking into account if any reactant is limiting
1 mole O2 produces 2 moles H2O (H2 is in excess so is not limiting)

Finally, using this mole ratio, calculate moles of product (H2O) that can be made from 2.15 moles O2
2.15 moles O2 x 2 moles H2O/2 moles O2 = answer