Chapter 8, Problem 8STP

Interpretation Introduction

Interpretation:

The required energy to break all the bonds present in given molecule is to be calculated.

Concept introduction:

The energy required to break a bond is termed as bond dissociation energy. The bond length depends on the bond dissociation energies. The longest bond has lowest bond energy and the shortest bond has highest bond energy.

Answer to Problem 8STP

The required energy to break all the bonds present in given molecule is $\text{5011}\text{kJ/mol}$.

Explanation of Solution

Reason for correct option: The given molecule is shown below.

In the given molecule, there are two $\text{N-H}$ bond, four $\text{C-H}$ bond, one $\text{C-N}$ bond, two $\text{C-C}$ bond, one $\text{C=O}$ bond, one $\text{C-O}$ bond, and one $\text{O-H}$ bond.

The required energy to break all the bonds present in given molecule is calculated as shown below.

$E_{\text{total}}=2E_{\text{N-H}}+4E_{\text{C-H}}+E_{\text{C-N}}+2E_{\text{C-C}}+E_{\text{C=O}}+E_{\text{C-O}}$

The value of dissociation energy is shown below.

Substitute the given data in above equation.

$\begin{array}{c}{E}_{\text{total}}=2E_{\text{N-H}}+4E_{\text{C-H}}+E_{\text{C-N}}+2E_{\text{C-C}}+E_{\text{C=O}}+E_{\text{C-O}}+E_{\text{O-H}}\\ =2\times 391\text{kJ/mol}+4\times 416\text{kJ/mol}+305\text{kJ/mol}+2\times 345\text{kJ/mol}+745\text{kJ/mol}+358\text{kJ/mol}+467\text{kJ/mol}\\ =782\text{kJ/mol}+1664\text{kJ/mol}+305\text{kJ/mol}+690\text{kJ/mol}+745\text{kJ/mol}+358\text{kJ/mol}+467\text{kJ/mol}\\ E_{\text{total}}=\text{5011}\text{kJ/mol}\end{array}$ Therefore, option (D) is the correct option.

Conclusion

Reason for incorrect option: The required energy to break all the bonds present in given molecule is $\text{5011}\text{kJ/mol}$. So, A is incorrect option.

The required energy to break all the bonds present in given molecule is $\text{5011}\text{kJ/mol}$. So, B is incorrect option.

The required energy to break all the bonds present in given molecule is $\text{5011}\text{kJ/mol}$. So, C is incorrect option.