Using the bond dissociation energies given,calculate DH° for the following reaction.
A)+108 KJ/mol
B)-130 KJ/mol
C)-22 KJ/mol
D)+22 KJ/mol

Question

Using the bond dissociation energies given,calculate DH° for the following reaction.  
A)+108 KJ/mol 
B)-130 KJ/mol 
C)-22 KJ/mol 
D)+22 KJ/mol

Quizplus · Accepted Answer

DH° = Σ(energy required to break bonds) - Σ(energy released in forming bonds)

Breaking bonds:
4 C-H bonds: 413 kJ/mol x 4 = 1652 kJ/mol
1 O=O bond: 498 kJ/mol

Forming bonds:
2 C=O bonds: 799 kJ/mol x 2 = 1598 kJ/mol
2 H-O bonds: 463 kJ/mol x 2 = 926 kJ/mol

DH° = (1652 kJ/mol + 498 kJ/mol) - (1598 kJ/mol + 926 kJ/mol) = +22 kJ/mol
Therefore, the answer is D (+22 KJ/mol).

Using the Bond Dissociation Energies Given,calculate DH° for the Following