Question

Explain how you would calculate the total change in bond energy for the reaction H₂ + Cl₂ → 2HCI. How would you know if the reaction was endothermic or exothermic? State your answer in 3-5

Answer 1

Answer: The total change of the energy is -183 kJ/mol

Step-by-step explanation:

The way I would calculate the total change in the bond energy in the following steps:

- To calculate the whole change in the bond energy. By calculating the energies of the broken bonds and then the energy of the formed bonds.

-132 kJ/mol + 239 kJ/mol = a total of 671 kJ/mol broken bonds.

-H-CI: 2 x 427 = 854 kJ/mol

-Second to calculate the change in the bond energy we now need to subtract the total energy of the broken bond from the total energy of the formed bonds.

-Change in energy = 671 kJ/mol - 854 kJ.mol

-The total change of the energy is -183 kJ/

- Having the negative, therefore, means the reaction is exothermic.

Answer 2

The total change in energy is -183 kJ/mol, and the reaction is exothermic.

Explanation:

1st) To calculate the total change in bond energy, it is necessary to calculate the energy of the broken bonds (in the reactants side) and the energy of the formed bonds (in the products side):

• Energy of broken bonds:

H-H: 1 x 432 = 432 kJ/mol

Cl-Cl: 1 x 239 = 239 kJ/mol

Total energy of broken bonds = 432 kJ/mol + 239 kJ/mol

Total energy of broken bonds = 671 kJ/mol

• Energy of formed bonds:

H-Cl: 2 x 427 = 854 kJ/mol

Total energy of formed bonds = 854 kJ/mol

2nd) Now to calculate the total change in bond energy, we have to subtract the Total energy of broken bonds minus the total energy of the formed bonds:

Total change in energy = Total energy of broken bonds - Total energy of formed bonds

Total change in energy = 671 kJ/mol - 854 kJ/mol

Total change in energy = -183 kJ/mol

Finally, the total change in energy is -183 kJ/mol, and the negative sign means that the reaction is exothermic, because