Question Detail
Question
Calculate the standard enthalpy change for the reaction: N₂(g) + O₂(g) → 2NO(g) given the following standard enthalpies of formation: ΔHf°(NO) = 90.3 kJ/mol, ΔHf°(N₂) = 0, ΔHf°(O₂) = 0.
Correct Answer
Option B is the correct answer.
Detailed Explanation
ΔH°rxn = Σ ΔHf°(products) - Σ ΔHf°(reactants) = [2 × 90.3] - [0 + 0] = 180.6 kJ.
Hint
The enthalpy of formation of an element in its standard state is zero.