The steering rockets in space vehicles use N₂O₄ and a derivative of hydrazine, 1,1-dimethylhydrazine (Study Question 5.86). This mixture is called a hypergolic fuel because it ignites when the reactants come into contact:

(a) Identify the oxidizing agent and the reducing agent in this reaction.
(b) The same propulsion system was used by the Lunar Lander on moon missions in the 1970s. If the Lander used 4100 kg of H₂NN(CH₃)₂, what mass (in kilograms) of N₂O₄ was required to react with it? What mass (in kilograms) of each of the reaction products was generated?

Data given in Question 86

Hydrazine and 1,1-dimethylhydrazine both react spontaneously with O₂ and can be used as rocket fuels.

The molar enthalpy of formation of N₂H₄(ℓ) is +50.6 kJ/mol, and that of N₂H₂(CH₃)₂(ℓ) is +48.9 kJ/mol. Use these values, with other Δ_f H° values, to decide whether the reaction of hydrazine or 1,1-dimethylhydrazine with oxygen provides more energy per gram.

Transcribed Image Text:

H₂NN(CH3)2() + 2 N₂O4(l) → 3 N₂(g) + 4H₂O(g) + 2 CO₂(g)