Stoichiometry Problems

Question

The reaction between hydrazine (N2H4) and hydrogen peroxide (H2O2) to produce nitric acid (HNO3) and water, is used in some rocket engines. If 1.5 mol of hydrazine was used, find...

a) # of moles of H2O2 required. (answer: 10.5 mol)

b) # of moles of HNO3 and H2O produced. (answer: 3 mol, 12 mol)

Answer 1

First, we should write the correctly balanced equation:

N₂H₄ + 7H₂O₂ ==> 2HNO₃ + 8H₂O ... balanced equation

a) we will use the stoichiometry of the balanced equation to find moles of H₂O₂ needed:

1.5 mol N₂H₄ x 7 mol H₂O₂/1 mol N₂H₄ = 10.5 moles H₂O₂ needed

b) again, we use the stoichiometry of the balanced equation for find moles of HNO₃ and H₂O produced:

1.5 mol N₂H₄ x 2 mol HNO₃/1 mol N₂H₄ = 3.0 mol HNO₃ produced

1.5 mol N₂H₄ x 8 mol H₂O/1 mol N₂H₄ = 12 mol H₂O produced