Question: how many moles of hydrogen gas would be needed to react with excess carbon dioxide to produce 76.6?
Answer: A Chemistry tutor answered he hydrogen is required both to react with the carbon and the oxygen and all of this must be accounted for to produce the 76.6 moles of water. From the equation 4 moles of hydrogen reacts with 1 mole of carbon dioxide to produce 2 moles of water.