Chapter 16, Problem 69A

Interpretation Introduction

Interpretation:

To distinguish between a complex reaction, a reaction mechanism and an elementary step.

Concept introduction:

Most chemical reactions made up of sequences of two or more simpler reactions. The reaction of ozone to produce oxygen occurs in three steps.

$\begin{array}{l}\text{step}\text{1}:{\text{Cl+O}}_{\text{3}}\to {\text{O}}_{\text{2}}\text{+ClO}\\ \text{step}\text{2:}{\text{O}}_3\to {\text{O+O}}_{\text{2}}\\ \text{step}\text{3:}\text{ClO+O}\to {\text{Cl+O}}_{\text{2}}\\ \text{Complex}\text{reaction:}{\text{2O}}_{\text{3}}\to 3{\text{O}}_{\text{2}}\end{array}$

Each step in the reaction is elementary step. Complex reaction is formed by adding all steps.

Answer to Problem 69A

A complex reaction is one that comprises of two or more elementary steps. A reaction mechanism is the complete series of elementary steps that makes a complex reaction. Each step of the complex reaction is termed as elementary step.

Explanation of Solution

A complex reaction is comprises of at least two or more elementary reactions. A complex reaction may look simple but may have many smaller reactions that took place in order to convert the original reactants to the final product. Complex reaction is formed by adding all the elementary reaction together. A reaction mechanism is the sum of total elementary chemical reactions which make a complex reaction. Each single step in both complex reaction and reaction mechanism is called elementary step.

Conclusion

Reaction mechanism is a collection of elementary reaction while complex reaction is the net reaction which is formed by adding all elementary steps.