Chapter U5.104, Problem 5E

Interpretation Introduction

Interpretation: The total energy required to break all the bonds in 1 mol of ethanol $\left({\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{O}\right)$ needs to be calculated.

Concept introduction: The total bond energy is given as the summation of all the bond energy in the molecule.

Answer to Problem 5E

The total energy required to break all the bonds in 1 mol of ethanol ${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{O}$ is 3218 kJ.

Explanation of Solution

The molecule ethanol contains 5 $\text{C-H}$ bond, 1 $\text{O-H}$ and one $\text{C-O}$ bond.

The total energy can be calculated as,

  $\begin{array}{c}\text{Total bond energy}\left(\text{E}\right)\text{=}\text{5×}\left(\text{C-H}\text{bond}\text{energy}\right)\text{+}\left(\text{O-H}\text{bond}\text{energy}\right)\text{+}\left(\text{C-O}\text{}\text{bond}\text{energy}\right)\text{+}\left(\text{C-O}\text{bond}\text{energy}\right)\text{+}\left(\text{C-C}\text{bond}\text{energy}\right)\\ \text{=}\text{5×}\text{411}\text{+}\text{459}\text{+}\text{358}\text{+}\text{346}\\ \text{=}\text{3218}\text{kJ}\end{array}$

Conclusion

The requiredtotal energy to break all the bonds in 1 mol of ethanol ${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{O}$ is found out to be 3218 kJ.