GKFix MCQ Question

Which of the following reactions can reach equilibrium from both directions?

• A. 2H₂O(l) → 2H₂(g) + O₂(g)
• B. NaCl(s) → Na⁺(aq) + Cl⁻(aq)
• C. N₂(g) + 3H₂(g) ⇌ 2NH₃(g)
• D. Mg(s) + O₂(g) → MgO(s)