1. A transitional structure forms during the process of breaking old bonds and making new bonds. What is this structure called? 2. Sketch a potential energy curve for an endothermic reaction. Label the activated complex, activation energy, and the change in enthalpy. 3. When exposed to air, white phosphorous immediately and rapidly reacts with oxygen. What can you say about the activation energy of this reaction? 4. If fine copper wool is heated in a crucible, it will react with oxygen in order to form copper (II) oxide. However at room temperature, the copper wool does not appear to react. Compare the activation energy of the copper and oxygen reaction to that of the phosphorous and oxygen reaction. 5. Two molecules move rapidly, but slow down as they get close to each other. What causes this drop in speed? 6. The forward activation energy of a reaction is 75kJ/mole. Its reverse activation energy is 90kJ/mole. What is the H for the forward reaction? 7. Two molecules are about to collide with each other. (a) What is happening to their Kinetic Energies? (b) What is happening to their Potential Energies