Chapter 6.3, Problem 6.7PP

Interpretation Introduction

Interpretation:

For a reaction, an energy diagram needs to be drawn having a high E_a and value of $\Delta H=+20\text{ kcal/mol}$.

Concept Introduction:

In energy diagram, energy versus progress of the reaction-the reaction coordinates are plotted. Reactants are placed in the left side and products in right side. These reactants and products are connected by a smooth curve that represent how energy change with time.

When two reactions approach each other, a repulsion takes place, so the energy is increased until a maximum value is achieved. This state is called transition state and energy difference between the transition state and reactants are called the activation energy, E_a. As the bonds form between the reactants, the energy decreases until a stable minimum energy is achieved. The difference in energy between the reactants and the products is the enthalpy change, ΔH.