Question Detail
Question
Calculate ΔH for the reaction H₂(g) + Cl₂(g) → 2HCl(g) using bond enthalpies: H-H = 436 kJ/mol, Cl-Cl = 243 kJ/mol, H-Cl = 431 kJ/mol.
Correct Answer
Option B is the correct answer.
Detailed Explanation
Bonds broken: 1 H-H (436) + 1 Cl-Cl (243) = 679 kJ. Bonds formed: 2 H-Cl (2 × 431 = 862 kJ). ΔH = 679 - 862 = -183 kJ.
Hint
The notes provide this exact calculation.