Hydrazine,N₂H₄,once used as a rocket propellant,reacts with oxygen in the following equation. N₂H₄(g) + O₂(g) → N₂(g) + 2 H₂O(g)
The reaction,at 50% yield,produces 4.0 moles of N₂.What was the mass of hydrazine used? Assume that O₂ is in excess.

Question

Quizplus · Accepted Answer

According to the balanced equation, 1 mole of N₂ reacts with 1 mole of O₂ to produce 2 moles of H₂O. Since N₂ is produced with a 50% yield, it means that only half of the hydrazine actually reacted, and the other half was left unreacted. Therefore, the initial amount of hydrazine used was 8.0 moles (2 x 4.0 moles). The molar mass of hydrazine (N2H4) is 32 g/mol. Therefore, the mass of 8.0 moles of hydrazine is: 8.0 moles x 32 g/mol = 256 g Therefore, the correct answer is choice B (260 g).

Hydrazine,N2H4,once Used as a Rocket Propellant,reacts with Oxygen in the Following

Hydrazine,N₂H₄,once Used as a Rocket Propellant,reacts with Oxygen in the Following