1.1: Introduction- Reaction Kinetics 1.2: Reaction Rates 1.3: Activation Barriers There are a number of factors that influence reaction rates, but the first one that we will look at is the activation barrier. An activation barrier is a sort of energetic hurdle that a reaction must get over. Some reactions have higher hurdles and some have lower hurdles. It's much easier to get over lower hurdles, so reactions with low activation barriers can proceed more quickly than ones with higher activation barriers. 1.4: Collisions and Phase 1.5: Collisions and Concentration We know that in order for two molecules to react with each other, they must first contact each other. We think of that contact as a "collision". The more mobile the molecules are, the more likely they are to collide. Also, the closer the molecules are together, the more likely they are to collide. 1.6: Rate Laws 1.7: Elementary Reactions The mechanism of a reaction is a series of steps leading from the starting materials to the products. After each step, an intermediate is formed. The intermediate is short-lived, because it quickly undergoes another step to form the next intermediate. These simple steps are called elementary reactions. Because an overall reaction is composed of a series of elementary reaction, the overall rate of the reaction is dependent on the rates of those smaller reactions. 1.8: Catalysis The mechanism of a reaction is a sequence of elementary steps leading from the starting materials to a series of intermediates and eventually to the products. Each step involves an activation barrier. Each intermediate has some measure of stability. We can keep track of energy changes along this reaction pathway by using a reaction progress diagram. 1.9: Solutions to Selected Problems