Unformatted text preview: Assume that the absolute energy associated with the reactants is 0 kcal/mol. In your reaction energy diagram, label the positions of the reactants (as R ), the products (as P ), and the transition state ( ‡ ). Also label Δ H in your diagram. Three possible structures of the transition state are shown to the right of the reaction energy diagram template. Circle the structure which best represents the transition state, based on your estimate of Δ H and Hammond’s postulate. A dotted line represents a partial bond. Energy (kcal/mol) Reaction Progress 0 +20 – 20 – 40 HO C Br H H H H C H H Br HO C HO H H H Br Bond broken = H 3 C–Br (BDE = 72 kcal/mol) Bond formed = H 3 C–OH (BDE = 92 kcal/mol) –20 R P ‡ Δ H According to Hammond’s postulate, the transition state for an exothermic reaction step resembles reactants more than products....
View Full Document
This homework help was uploaded on 04/11/2008 for the course CH 310M taught by Professor Iverson during the Spring '05 term at University of Texas.
- Spring '05