FOURTEENTH EDITION CHEMISTRY Mc Graw Hill Jason Overby Raymond Chang Chapter 13 Chemical Kinetics Part 1 Dr. Muzaffer Tonguç Öztek Valencia College Reaction Kinetics: how fast? Rate: how fast do

concentrations change during a reaction: Rusting of iron: relatively slow - Explosion of natural gas: relatively fast ● ● Energy Reactants KINETICS Intermediate states, speed THERMODYNAMICS Initial and final states, spontaneity Reaction progress Products Thermodynamics: Feasibility, will it happen or not (initial and final states) Kinetics: If it happens, how fast will it happen (intermediates) 2 Purpose of studying kinetics Our main interest is: Conditions affecting reaction rates Understand the molecular events occurring during the reaction. So that we can control chemical reactions Make them faster or slower We can calculate: the time needed for a chemical reaction to reach the desired completion. the concentration after a known amount of time into the reaction 3 How Do Reactions Happen (Collision Theory) Reactant molecules collide with enough energy and proper orientation to form the products. 1. Minimum energy requirement - Activation energy, E. (energy barrier) AINSING ARCH THEY NESPONDE Potential energy reactants intermediate Ea products Reaction pathway Potential energy diagram 13| 4 energy Potential A+B → AB →C+D Exothermic Reaction E a AB÷ AB÷ Ea C+D Å Å A + B A + B Reaction progress (a) C + D Endothermic Reaction Potential energy Reaction progress (b)