Question Detail
Question
Given the standard enthalpies of formation: ΔHf°[NH₃(g)] = -46 kJ/mol, ΔHf°[HCl(g)] = -92 kJ/mol, ΔHf°[NH₄Cl(s)] = -314 kJ/mol. Calculate ΔH° for the reaction: NH₃(g) + HCl(g) → NH₄Cl(s).
Correct Answer
Option A is the correct answer.
Detailed Explanation
ΔH°rxn = Σ ΔHf°(products) - Σ ΔHf°(reactants) = [-314] - [(-46) + (-92)] = -314 - (-138) = -314 + 138 = -176 kJ.
Hint
ΔH°rxn = Σ ΔHf°(products) - Σ ΔHf°(reactants).