Suppose you want to make 100 grams of water.  How much hydrogen and Oxygen would you need to make 100 grams of water with nothing left over.  Explain.

Expert Answers
justaguide eNotes educator| Certified Educator

The chemical formula of water is H2O. One molecule of water has 2 atoms of hydrogen and one atom of oxygen.

1 mole of water requires 1 mole of hydrogen (H2) and 0.5 moles of oxygen (O2).

The molar mass of water is 100/18

This requires 100/18 moles of hydrogen. As the molar mass of hydrogen is 2, it requires 200/18 = 100/9 g of hydrogen.

It requires 0.5*100/18 mole of oxygen. The molar mass of oxygen is 32. The mass of oxygen required is 800/9 g

It requires 100/9 g of hydrogen gas and 800/9 g of oxygen gas to make 100 g of water.