GKFix MCQ Question

For the reaction N₂(g) + 3H₂(g) → 2NH₃(g), ∆rH⁰ = –91.8 kJ mol⁻¹. What is ∆rH⁰ for 2NH₃(g) → N₂(g) + 3H₂(g)?

• A. –91.8 kJ mol⁻¹
• B. –45.9 kJ mol⁻¹
• C. +91.8 kJ mol⁻¹
• D. +45.9 kJ mol⁻¹