Use the bond energies below to determine whether the following reaction is exothermic or endothermic: $\mathrm { H } _ { 2 }$ + $\mathrm { Cl } _ { 2 }$ ? 2 HCl H-H (bond energy: 436 kJ/mol)
Cl-Cl (bond energy: 243 kJ/mol)
H-Cl (bond energy: 431 kJ/mol)
A)Exothermic with more than 50 kJ of energy released.
B)Endothermic with more than 50 kJ of energy absorbed.
C)Exothermic with less than 50 kJ of energy released.
D)Endothermic with less than 50 kJ of energy absorbed.

Question

Quizplus · Accepted Answer

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

Use the Bond Energies Below to Determine Whether the Following H2\mathrm { H } _ { 2 }H2​

Use the Bond Energies Below to Determine Whether the Following $\mathrm { H } _ { 2 }$