GKFix MCQ Question

Which of the following reactions has ∆H = ∆U?

• A. C(s) + O2(g) → CO2(g)
• B. 2H2(g) + O2(g) → 2H2O(l)
• C. N2(g) + 3H2(g) → 2NH3(g)
• D. CaCO3(s) → CaO(s) + CO2(g)