Answer the following questions about the mechanism for the acid-catalyzed hydration of an alkene:

a. How many transition states are there?
b. How many intermediates are there?
c. Which step in the forward direction has the smallest rate constant?

Respuesta :

Answer:

a) there are three transition states

b) there are two intermediates; carbocation and protonated alcohol

c) The first step in the forward direction

Explanation:

The acid-catalysed hydration of alkenes proceeds via a carbocation mechanism.

Three transition states can be identified in this mechanism for the acid-catalyzed hydration of alkenes.

The three transition states are derived from the three steps in the reaction sequence:

1) Protonation of the alkene by hydronium ion

2) Addition of water to the carbocation

3) loss of a proton to yield the alcohol

The first step involves the breaking of a pi bond, hence it is a slow step hence it has the smallest rate constant. The other two steps are fast steps.