1. The reaction between an ester and an alkoxide, such as:

is a reversible reaction where one RO- group replaces another.  The equilibrium constant for this reaction is close to 1.  The mechanism (written in the forward direction) is as follows:

(a)  Draw a reaction coordinate diagram for the reaction, assuming that the equilibrium constant is exactly 1.00 and also that DS = 0.  Mark on the diagram both the DH and the E_act for the overall reaction.

2.  The reaction

where Ph represents a phenyl group (C₆H₅-), can be represented on a reaction coordinate diagram as follows:

(a)  Is the reaction endothermic or exothermic?  Explain how you can deduce this from the diagram above.

(b)  Write the complete mechanism for the reaction based on the above diagram.  Indicate which step is the rate determining step.

(c)  Write the rate law for this reaction.  What would be the effect of doubling the concentration of alkyl bromide?  Of doubling the CH₃CH₂O ^- ion concentration?

(d)  Explain the role of the CH₃CH₂O^- ion in this reaction in terms of the Bronsted-Lowry theory.

3. Two alternative irreversible reactions (shown below) have the following mechanism:-

E is more stable than F, yet F is the major product (90%), only 10% of E is formed.
(a) What is the rate determining step in the formation of F?
(b) What is the reaction order for the reaction A+B ----> F?
(c) Draw a reaction coordinate diagram for showing both A+B --> E and A+B --> F.
(d) Label the activation energy for the reaction A+B --> F, for the rate determining step only. Also label ?H for this reaction. Explain why the less stable product F is major.