Use the table to answer the question:
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 or exothermic? State your answer in 3-5 sentences.
(2 points)
To calculate the total change in bond energy for the reaction H2 + Cl2 -> 2HCl, you would first determine the total bond energy of the reactants (H-H + Cl-Cl) and then subtract the total bond energy of the products (2H-Cl). In this case, the total bond energy of the reactants is (432 + 239) = 671, and the total bond energy of the products is (2 * 427) = 854. Therefore, the total change in bond energy is 854 - 671 = 183.
To determine if the reaction is endothermic or exothermic, you would observe whether the total change in bond energy is positive or negative. If the total change in bond energy is positive (as in this case), it means that more energy was absorbed to break the bonds in the reactants than released when new bonds were formed in the products. Thus, the reaction is endothermic. Conversely, if the total change in bond energy were negative, it would indicate that more energy was released when new bonds were formed than was absorbed to break the bonds, making the reaction exothermic.