CHEM 113 Exam # 1 Study Guide Lectures: 1 - 7Chapter 16 Kinetics: Rate and Mechanisms of Chemical ReactionsLecture 1 (August 25)- 16.1: Focusing on Reaction Rateo What is a reaction rate? The change in the concentrations of reactants (or products) as a function of time. Under a given set of conditions, each reaction has its own rate.o What are the factors that affect reaction rate and how do they affect reaction rate? Concentration affects rate by influencing the frequency of collisions between reactant molecules. Physical state affects rate by determining how well reactants can mix. Temperature affects rate by influencing the frequency and more importantly the energy of the collisions between reactant molecules.Lecture 2 (August 27)- 16.2: Expressing the Reaction Rateo The reaction rate is measured in terms of changes in concentrations of reactants or products per unit of time.o There are three ways to describe rate Average rate Instantaneous rate Initial rate- 16.3: The Rate Law and its Componentso What is the rate law and what is it describing? Rate= k[A]^m[B]^n It expresses the rate as a function of concentrations and temperature.o Reaction orders Each reactant gets and order There are three types of orders- First order- Second order- Zero order The overall order of a reaction can be calculated by adding up the reaction orders of each reactant.Lecture 3 (August 29)- 16.3: The Rate Law and its Components Conto Solving for the rate law Here is a general plan for solving various components of the rate law 1). Given: Series of plots of concentration vs. time- From this we determine the slope of the tangent at t0, giving us the initial rate for each plot. This was discussed the in previous lecture. 2). Given/Found: Initial rates- We then compare the initial rates when the concentration of A changes and B is held constant and vice versa. This gives us the reaction orders. This step is explained in more detail in the next section. 3). Given/Found: concentrations and reaction orders- We then can plug them into the rate law and solve for our rate constant k.o The units for k depend on the order. 4). Given/Found: Initial rates, rate constant, orders, and concentrations ofall reactants- We then substitute these values into the rate law rate=k[A]^m[B]^n- 16.4: Integrated Rate Laws: Concentration Changes Over Timeo These include time as a variableo They differ depending on the order. First-order rate equation- ln ([A]0/[A]t) = -kt- [A]0= Initial concentration and [A]t= concentration at specific time. Second-order rate equation- (1/[A]t)-(1/[A]0) = kt Zero-order rate equation- [A]t-[A]0 = -kto Using these laws graphically  Each of these equations can be rearranged into y=mx+b form, which can then be used to identify values using a graph.Lecture 4 (September 3)- 16.4: Integrated Rate Laws: Concentration Changes Over Timeo Reaction Half-life The half-life (denoted: (t) subscript ½) for a reaction is the time taken for the concentration of a reactant to drop to half of its initial value. Half-life relationships vary from order to order.- First order: The half-life does not depend on the concentration- Second order: Depends inversely on initial concentration- Zero order: Depends directly on concentrationLecture 5 (September 5)- 16.5: Theories of Chemical Kineticso Collision Theory Particles must collide in order to react. The number of collisions depends on the product of the numbers of reactant particles, not their sum.- Therefore concentrations are multiplied in the rate law not added.o The Effect of Temperature on the Rate Constant and the Rate Experimental data shows that k increases exponentially as T increases, which is expressed in the Arrhenius equation.-k = Ae-Ea/RT Higher T larger k increased rateo Activation energy When particles collide effectively, they reach and activated state. The energy difference between the reactants and the activated state is the activation energy. The lower that activation energy, the faster the reaction.o The Effect of Temperature on Collision Energy An increase in temperature causes an increase in the kinetic energy particles. This leads to more frequent collisions and reaction rate increases. At a higher temperature, the fraction of collisions with sufficient energy equal to or greater than the activation energy increases. Therefore rate increases.o Calculating Activation Energy The Arrhenius equation is used to calculate or solve for activation energy. Can also be used if rate constants at two temperatures are given.o Molecular Structure and Reaction Rate For a collision between particles to be effective, it must have both sufficient energy and the appropriate relative orientation between the reacting particles. When looking at the Arrhenius equation, the A contains the molecular orientation and therefore is the frequency factor.- A= pZo Transition State Theory An effective collision between particles leads to the formation of a transition state. The transition state is an instable species that contains partial bonds. It is a transitional species partway between reactants and products. The transition state exists at the point of maximum potential energy.Lecture 6 (September 8)- 16.6: Reaction Mechanisms: The Steps from Reactant to Producto Reaction mechanisms The mechanism of a reaction is the sequence of single reaction steps that make up the overall equation. The individual steps of the reaction mechanism are called elementary steps because each one describes a single molecular event.- Each elementary step is characterized by its molecularity, the number of particles involved in the reaction.- Because an elementary reaction occurs in one step, its rate law, unlike that for an overall reaction, can be deduced from the reaction stoichiometry.o Correlating the Mechanism with the Rate Law A valid mechanism must meet three criteria:- The elementary steps must add up to the overall balanced equation.- The elementary steps must be reasonable.- The mechanism must correlate with the observed rate law.o The Rate-determining step of a reaction The slowest step in a reaction is the rate-determining or rate-limiting step. The rate law for the rate-determining step becomes the rate law for the overall reaction.Lecture 7 did not include any new material but