Question Detail
Question
A nitrogen-hydrogen mixture, initially in the mole ratio of 1:3 reached equilibrium with ammonia when 50% of the nitrogen had reacted. The total final pressure was p. What was the partial pressure of ammonia in the equilibrium mixture?
Correct Answer
Option B is the correct answer.
Detailed Explanation
N₂ + 3H₂ ⇌ 2NH₃. Initial moles: 1, 3, 0. Change: -0.5, -1.5, +1.0. Equilibrium moles: 0.5, 1.5, 1.0. Total moles = 3.0. Mole fraction NH₃ = 1/3. Partial pressure = (1/3)p = p/3.
Hint
Use the stoichiometry to find equilibrium moles, then mole fractions.