Liquid hydrazine, N¿Hs, has been used as a fuel for rockets. When the rocket is to be
launched, a catalyst causes the liquid hydrazine to decompose quickly into elemental
nitrogen and hydrogen gases. The rapid expansion of the product gases and the heat
released by the reaction provide the thrust for the rocket. What is the balanced equation for
this reaction of hydrazine to produce nitrogen and hydrogen gases?
N2H4 (l) → N2 (g) + 2H2 (g)
That balances the equation; however, you should be aware that in a rocket set up the N2H4 actually burns with oxygen.
N2H4(g) + O2(g) → N2(g) + 2H2O(g)