Chapter 6, Problem 46DSP

Interpretation Introduction

Interpretation:

The equation including the curved arrows that best represents the rate determining step in the mechanism is to written.

Concept Introduction:

The slowest step in the substitution reaction is the rate determining step.

For the substitution reactions by an ${\text{S}}_{\text{N}}2$ pathway, the slow step which is the rate determining step is bimolecular. Thus, it must include both, the alkyl halide and the nucleophile.

Thus, ${\text{S}}_{\text{N}}2$ mechanism is a one step process in which both the alkyl halide and the nucleophile are involved in the rate determining step.

Curved arrows indicate the movement of electrons in a mechanism.

Primary carbocations are not stable and so, they do not form as a carbocation intermediate in a given mechanism.