Chapter 17, Problem 1A

Interpretation Introduction

Interpretation: Types of bonds that cleaves and forms in ${\text{H}}_{\text{2}}$ and ${\text{Br}}_{\text{2}}$ to form $\text{HBr}$ has to be listed.

Concept introduction: For a reaction to occur, reactants must cross a barrier of energy called threshold energy. If a molecule has energy less than threshold value, it had to given some additional energy to cross the barrier. This additional energy is activation energy. When reactants acquire energy, they become unstable and bonds are loosened. This state is called activated complex. On product formation, bond break ultimately and energy is released.

Answer to Problem 1A

The bond between 2 hydrogen atoms in ${\text{H}}_{\text{2}}$ and 2 bromine atoms in ${\text{Br}}_{\text{2}}$ is broken and new bond between hydrogen and bromine is formed.

Explanation of Solution

The reaction of ${\text{H}}_{\text{2}}$ and ${\text{Br}}_{\text{2}}$ to form $\text{HBr}$ occurs as follows:

  

Conclusion

The bond between 2 hydrogen atoms in ${\text{H}}_{\text{2}}$ and 2 bromine atoms in ${\text{Br}}_{\text{2}}$ is broken and new bond between hydrogen and bromine is formed.