Chem 12 Unit 1 - Reaction Kinetics Sec 1.10 PE Diagram for a Reaction Mechanism teacher AC (step 1) see p. 26 SW AC (step 2) see p.27 AC (step 3) see p. 27 HOOBr PE HOBr HBr + O2 STEP 1 STEP 2 STEP 3 H2O + Br2 REACTION PROCEEDS Notes: each “bump” is a step the higher the bump, (greater Ea) the slower the step the highest bump (from the reactants level) is for the RDS AC’s at top of bumps, intermediates in middle “valleys”, products in the final “valley” the Ea for the forward overall rxn. is vertical distance from reactants to top of highest bump. On the diagram for this mechanism at the top of the page, label the Rate Determining Step. Draw an arrow to show the Ea (overall reaction) . Label it. Draw another labeled arrow to show the Ea for Step 1. Draw a labeled arrow to show for the overall reaction. PE REACTION PROCEEDS In each of the reactions in the diagram above, the Ea for the overall forward reaction is the difference in energy between the reactants and the top of the highest peak. Chem 12 Unit 1 - Reaction Kinetics Question: Given the following Potential Energy Diagram for a reaction mechanism: PE (KJ) 80 70 60 50 Reaction Proceeds 1. This mechanism has 3. Step steps is the RDS 5. The overall rxn. is 6. = 2. Ea for overall rxn = 4. Step kJ is the fastest step. thermic kJ 7. for reverse rxn. = kJ 9. RDS for reverse rxn. is step Draw a Potential Energy Diagram for a reaction mechanism with 2 steps. The first step is fast and the second step is slow. The overall reaction is exothermic. and the for the forward reaction. PE Reaction Proceeds Read p. 29-30 in SW. Do Ex. 54 and 55 on page 30 of SW. Chem 12 Unit 1 - Reaction Kinetics Sec 1.10 PE Diagram for a Reaction Mechanism student AC (step 1) see p. 26 SW AC (step 2) see p.27 AC (step 3) see p. 27 HOOBr PE HOBr HBr + O2 STEP 1 STEP 2 STEP 3 H2O + Br2 REACTION PROCEEDS Notes: each “bump” is a step the higher the bump, (greater Ea) the slower the step the highest bump (from the reactants level) is for the RDS AC’s at top of bumps, intermediates in middle “valleys”, products in the final “valley” the Ea for the forward overall rxn. is vertical distance from reactants to top of highest bump. On the diagram for this mechanism at the top of the page, label the Rate Determining Step. Draw another labeled arrow to show the Ea for Step 1. Draw a labeled arrow to show for the overall reaction. PE REACTION PROCEEDS In each of the reactions in the diagram above, the Ea for the overall forward reaction is the difference in energy between the reactants and the top of the highest peak. Chem 12 Unit 1 - Reaction Kinetics Question: Given the following Potential Energy Diagram for a reaction mechanism: PE (KJ) 80 70 60 50 Reaction Proceeds 1. This mechanism has 3. Step steps 2. Ea for the forwards rxn = is the RDS 4. Step thermic 6. = 5. The overall rxn. is 7. for reverse rxn. = kJ kJ is the fastest step. kJ 9. RDS for reverse rxn. is step Draw a Potential Energy Diagram for a reaction mechanism with 2 steps. The first step is fast and the second step is slow. The overall reaction is exothermic. Lable the for the forward reaction and the Ea for each step. PE Reaction Proceeds Read p. 29-30 in SW. Do Ex. 54 and 55 on page 30 of SW.