# Problem: Hydrazine (N2H4) is a fuel used by some spacecraft. It is normally oxidized by N2O4 according to the following equation: N2H4(l) + N2O4(g) → 2 N2O(g) + 2 H2O(g). Calculate ΔH˚rxn for this reaction using standard enthalpies of formation.

###### FREE Expert Solution

We’re being asked to determine the standard enthalpy change (ΔH˚rxn) for the balanced reaction

N2H4(l) + N2O4(g) → 2 N2O(g) + 2 H2O(g)

Recall that ΔH˚rxn can be calculated from the enthalpy of formation (ΔH˚f) of the reactants and products involved:

$\overline{){\mathbf{∆}}{\mathbf{H}}{{\mathbf{°}}}_{{\mathbf{rxn}}}{\mathbf{=}}{\mathbf{∆}}{\mathbf{H}}{{\mathbf{°}}}_{\mathbf{f}\mathbf{,}\mathbf{products}}{\mathbf{-}}{\mathbf{∆}}{\mathbf{H}}{{\mathbf{°}}}_{\mathbf{f}\mathbf{,}\mathbf{reactants}}}$

###### Problem Details

Hydrazine (N2H4) is a fuel used by some spacecraft. It is normally oxidized by N2O4 according to the following equation: N2H4(l) + N2O4(g) → 2 N2O(g) + 2 H2O(g). Calculate ΔH˚rxn for this reaction using standard enthalpies of formation.