How many grams of water are produced by reacting 15.8 g H2 with excess oxygen?

24g H2 x 1 mol H2 x 2 mol H2O x 18g H2O/ 2g H2 x 2 mol H20= 216 g H2O

160g O2 x 1 mol O2 x 2 mol H2O x 18g H2O/ 32g O2 x 1 mol O2 x 1 mol H2O= 180 g H2O