Chapter 6.SE, Problem 42AP

Interpretation Introduction

Interpretation:

Given that 2-chloro-2-methylpropane reacts with water in three steps to yield 2-methyl-2-propanol. The first step is slower than second, which in turn is much slower than the third. The reaction takes place slowly at room temperature and the equilibrium constant is approximately 1. For this reaction a) The approximate value of ΔG^# and ΔG⁰ are to be given and b) An energy diagram labeling all points of interest and making sure that the relative energy levels on the diagram consistent with the information given is to be drawn.

Concept introduction:

Energy diagrams are used to depict graphically the energy changes that occur during a reaction. The vertical axis of the diagram represents the energy of all the reactants and the horizontal axis, called reaction coordinate, represents the progress of the reaction from beginning to end. The reactants are shown in left and the products in the right. The transition state represents the highest energy structure involved in the particular step reaction. The overall ΔG^# is the energy difference between the reactants and highest transition state. Reactions with low ΔG^# will occur at a faster rate. The overall ΔG⁰ is the free energy difference between the reactants and products. Every step in a reaction has a separate energy diagram.

Reactions with activation energies less than 80kJ/mol take place at or below room temperature.

To give:

The approximate value of ΔG^# and ΔG⁰ and to draw an energy diagram labeling all points of interest and making sure that the relative energy levels on the diagram consistent with the information provided for the reaction.(Given that 2-chloro-2-methylpropane reacts with water in three steps to yield 2-methyl-2-propanol. The first step is slower than second, which in turn is much slower than the third. The reaction takes place slowly at room temperature and the equilibrium constant is approximately 1).

ΔG⁰ and equilibrium constant (K_eq) are related as, ΔG⁰ = - RTln K_eq