Use the bond energies below to determine whether the following reaction is exothermic or endothermic: H₂ + Cl2 → 2 HCL
H-H (bond energy: 436 kJ/mol)
Cl-Cl (bond energy: 243 kJ/mol)
H-Cl (bond energy: 431 kJ/mol)

Question

Quizplus · Accepted Answer

To determine if the reaction is exothermic or endothermic, calculate the energy change: Energy required to break bonds - Energy released forming bonds. Breaking H-H (436 kJ/mol) and Cl-Cl (243 kJ/mol) requires 679 kJ. Forming 2 H-Cl bonds releases 2*431 = 862 kJ. The net release is 862 - 679 = 183 kJ, indicating an exothermic reaction with more than 50 kJ of energy released.

Use the Bond Energies Below to Determine Whether the Following