When 18.02 g of water is decomposed by electrolysis, 16.00 g of oxygen and 2.02 g of hydrogen are formed. According to the law of definite proportions, what masses, in grams, of (a) hydrogen and (b) oxygen will be formed by the electrolysis of 489 g of water?

You form water vapor by mixing oxygen and hydrogen at 730°c in a 5.4-liter container. this is the equation for the reaction: o2(g) + 2h2(g) → 2h2o(g). the partial pressure of oxygen before the reaction is 122.3 kilopascals, and there is excess hydrogen. how many moles of water are formed?