Answer to Question #293494 in General Chemistry for Cameron

Question

If 2.85 moles of H₂ and 1.55 moles of O₂ react how many moles of H₂O can be produced in the reaction below?

2 H₂(g) + O₂(g) → 2 H₂O(g)

Answer 1

2 moles H₂ react with 1 mol O₂ to form 2 moles of H₂O. Therefore the number of moles of O2 needed to react with 2.85 moles H₂ is;

Moles of O₂= 2.85 moles of H₂ * 1 mol of O2/2 moles of H2 = 1.425 moles of O2

1.55 moles of O2 are present before the reaction,

1.55 moles of O2- 1.425 moles of O2= 0.125 moles of O2 remain when the H2 is consumed

H2 is the limiting reactant.

Mol ratio of H2: O2: H2O is 2:1:2 therefore the moles of H2O produced are 2.85 moles.