For questions 14 - 16, assume the reaction occurs by the S N 2 mechanism. Write the rate expression for this reaction. Write a curved arrow mechanism for this reaction. Draw the transition state for the rate-determining step of this reaction. Transition states exist for only a very short period of time, yet we have spent a significant amount of time discussing them.
Transition states control the rate of a reaction.
Reaction rate can be measured in the laboratory, and is an important consideration when trying to apply a particular reaction. Assume the reactions are studied under conditions that allow only the S N 2 reaction to operate. We need to consider the differences between the three reactions, and how these differences influence the rate of an S N 2 reaction. Increasing steric hindrance at the carbon bearing the leaving group retards the rate of an S N 2 reaction. A tertiary carbon is so highly hindered to S N 2 attack that no reaction occurs.