Chapter 7, Problem 52P

Consider the following ${\text{S}}_{\text{N}}\text{2}$ reaction.

a. Draw a mechanism using curved arrows.

b. Draw an energy diagram. Label the axes, the reactants, products, $E_{\text{a}}$, and $\Delta H^{\text{ο}}$. Assume that the reaction is exothermic.

c. Draw the structure of the transition state.

d. What is the rate equation?

e. What happens to the reaction rate in each of the following instances? [1] The leaving group is changed from ${\text{Br}}^{-}$ to ${\text{I}}^{-}$; [2] The solvent is changed from acetone to ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$; [3] The alkyl halide is changed from ${\text{CH}}_{\text{3}}{\left({\text{CH}}_{\text{2}}\right)}_{\text{4}}\text{Br}$ to ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{CH}\left(\text{Br}\right){\text{CH}}_{\text{3}}$; [4] The concentration of ${}^{-}\text{CN}$ is increased by a factor of five; and [5] The concentrations of both the alkyl halide and ${}^{-}\text{CN}$ are increased by a factor of five.