In the reaction above, 1,443 kJ/mol of energy was absorbed to break the bonds of N2 and O2. 1,260 kJ/mol of energy was released when the N=O bonds in NO were formed. Use the formula above to calculate the total bond energy for the reaction. Use the value of the total bond energy for the reaction to decide if the reaction is endothermic or exothermic.
A.
The total bond energy of the reaction is + 183 kJ/mol and the reaction is endothermic.
B.
The total bond energy of the reaction is + 183 kJ/mol and the reaction is exothermic.
C.
The total bond energy of the reaction is + 2,703 kJ/mol and the reaction is endothermic.
D.
The total bond energy of the reaction is + 2,703 kJ/mol and the reaction is exothermic.
To calculate the total bond energy for the reaction, we sum the energy absorbed to break the bonds (1,443 kJ/mol) and the energy released when the bonds in the product are formed (1,260 kJ/mol):
Total bond energy = Energy absorbed - Energy released
Total bond energy = 1,443 kJ/mol - 1,260 kJ/mol
Total bond energy = 183 kJ/mol
Since the total bond energy is positive (183 kJ/mol), it means that more energy is required to break the bonds than is released when the new bonds are formed. This indicates that the reaction is endothermic, requiring an input of energy for the reaction to occur.
Therefore, the correct answer is:
A. The total bond energy of the reaction is + 183 kJ/mol and the reaction is endothermic.