Question

For the reaction taking place at certain temperature NH₂COONH₄(s) rightleftharpoons 2NH₃(g) + CO₂(g), if equilibrium pressure is 3X bar, then Δ G^∘ would be:

• A. \( -RT\ln 9 - 3RT\ln X \)
• B. \( RT\ln 4 - 3RT\ln X \)
• C. \( -3RT\ln X \)
• D. None of these

Hint:

Only gaseous species appear in Kp.

Answer 1

The Correct Option is C

Step 1: For the reaction, total gaseous moles =3.
Step 2: Δ G^∘ = -RTln Kp
Step 3: Since partial pressures are proportional to X, Kp ∝ X³ ⟹ Δ G^∘ = -3RTln X