Bond: Bond Energy:
H-H 432
Cl-Cl 239
H-Cl 427
Explain how you would calculate the total change in bond energy for the reaction H2+Cl2->2HCl. How would you know if the reaction was endothermic of exothermic? State your answer in 3-5 sentences.
To calculate the total change in bond energy for the reaction, we first need to calculate the total bond energy of the reactants and the total bond energy of the products.
In this case, the reactants are H2 and Cl2, which have bond energies of 432 and 239, respectively. The products are 2HCl molecules, each with a bond energy of 427.
Therefore, the total bond energy of the reactants is 432+239=671, and the total bond energy of the products is 2*(427)=854.
To find the total change in bond energy, we subtract the total bond energy of the reactants from the total bond energy of the products: 854-671=183.
Since the total change in bond energy is positive (183), this means that the reaction is exothermic. This is because energy is released in the form of heat during the reaction.