Use the table to answer the question:
Bond
H-H
CI-CI
H-CI
Bond energy
432
239
427
Explain how you would calculate the total change in bond energy for the reaction H_{2} + C*l_{2} -> 2HCl How would you know if the reaction was endothermic or exothermic?
To calculate the total change in bond energy for the reaction H_{2} + CI_{2} -> 2HCl, you need to calculate the difference in bond energy between the reactants and the products.
Reactants:
H-H bond energy = 432
CI-CI bond energy = 239
Total bond energy in reactants = 432 + 239 = 671
Products:
H-Cl bond energy = 427
Total bond energy in products = 427 * 2 = 854
Total change in bond energy = Total bond energy in products - Total bond energy in reactants
= 854 - 671
= 183
To determine if the reaction is endothermic or exothermic based on the change in bond energy, you need to consider the sign of the total change in bond energy.
If the total change in bond energy is positive (as in this case, 183), it indicates that more energy is required to break the bonds in the reactants than energy released when forming bonds in the products. This means the reaction is endothermic.
If the total change in bond energy is negative, it indicates that more energy is released during bond formation in the products than energy required to break the bonds in the reactants. This implies the reaction is exothermic.