GKFix MCQ Question

Which of the following reactions represents a standard molar enthalpy of formation (∆fH°)?

• A. CaO(s) + CO2(g) → CaCO3(s)
• B. H2(g) + Br2(l) → 2HBr(g)
• C. C(graphite, s) + 2H2(g) → CH4(g)
• D. 2C(graphite, s) + 3H2(g) + ½O2(g) → C2H5OH(l)