Chapter 27, Problem 73IAE

Interpretation Introduction

Interpretation:

The ethyl iodide formation in the presence of an excess of $\text{HI}$ and not with ${\text{I}}^{-}$ alone should be explained.

Concept introduction:

Replacement of a nucleophile comes under the category of nucleophilic substitution. Further substitution of iodide involves bimolecular nucleophilic substitution $\left({\text{S}}_{\text{N}}2\right)$.

The nucleophilic substitution reaction $\left({\text{S}}_{\text{N}}2\right)$ is a single step substitution reaction in which electron rich species substitute leaving group. The attack takes place from the back side of the electrophilic center thus there is an inversion of the configuration takes place. Also, there is a single transition state because bond breaking and bond making occurs simultaneously.