Consider the gaseous equilibrium for the dimerization of NO₂ at 350 K.
2 NO₂(g) ⇌ N₂O₄(g)What is the value of ΔG when NO₂ = 1.23 atm and N₂O₄ = 2.45 atm? Use the following ΔG° values:
ΔG° (NO₂(g)) = 51.3 kJ/molΔG° (N₂O₄(g)) = 99.8 kJ/mol
In which direction (forward or reverse) this reaction is spontaneous under the given conditions?

• A. ΔG = 3.15 kJ
  Since the value of ΔG is positive, the reaction is spontaneous in the reverse direction.
• B. ΔG = 1.95 kJ
  Since the value of ΔG is positive, the reaction is spontaneous in the reverse direction.
• C. ΔG = −1.40 kJ
  Since the value of ΔG is negative, the reaction is spontaneous in the forward direction.
• D. ΔG = −2.85 kJ
  Since the value of ΔG is negative, the reaction is spontaneous in the forward direction.

Answer: (C)