To calculate the total reaction energy for the reaction H2 + Cl2 -> 2HCl, we need to determine the individual bond energies of all the bonds broken and formed in the reaction.
The bond energies are as follows:
H-H: 436 kJ/mol (two H-H bonds are broken)
Cl-Cl: 242 kJ/mol (one Cl-Cl bond is broken)
H-Cl: 431 kJ/mol (two H-Cl bonds are formed)
Step 1: Calculate the energy required to break the bonds in the reactants:
Energy required = (2 * H-H bond energy) + (1 * Cl-Cl bond energy)
Energy required = (2 * 436 kJ/mol) + (1 * 242 kJ/mol)
Energy required = 872 kJ/mol + 242 kJ/mol
Energy required = 1114 kJ/mol
Step 2: Calculate the energy released when new bonds are formed in the products:
Energy released = (2 * H-Cl bond energy)
Energy released = (2 * 431 kJ/mol)
Energy released = 862 kJ/mol
Step 3: Calculate the total reaction energy:
Total reaction energy = Energy released - Energy required
Total reaction energy = 862 kJ/mol - 1114 kJ/mol
Total reaction energy = -252 kJ/mol
Therefore, the total reaction energy for the reaction H2 + Cl2 -> 2HCl is -252 kJ/mol. This negative sign indicates that the reaction is exothermic, meaning it releases energy during the reaction.
2. Calculate the total reaction energy for the reaction H2+CI2=2HCI
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