# Lecture 19: Introduction to Kinetics First a CH 302 Kinetics Study Guide (Memorize these first three pages, they are all the background you need)

Save this PDF as:

Size: px
Start display at page:

Download "Lecture 19: Introduction to Kinetics First a CH 302 Kinetics Study Guide (Memorize these first three pages, they are all the background you need)"

## Transcription

1 Lecture 19: Introduction to Kinetics First a CH 302 Kinetics Study Guide (Memorize these first three pages, they are all the background you need) Reaction Rate: The most important issue in kinetics is a determination of the rate of a reaction and the data that comes from a plot of the rate data. In the concentration-time plot below for the reaction aa bb [ ] [B] [A] time - Δ[A] = _Δ[B] = rate aδt bδt The rate is simply how fast A disappears (note the negative sign) and B appears as a function of time. The instantaneous rate is simply the tangent line at any time (the slope.) The lower case a and b are the reaction coefficients and are constants that make sure that rates at which things appear and disappear are the same (conservation of matter.) Rate Laws (what affects the rate.) Of course you can ask the question, what factors affect the rate. There are four factors : [A] x which is the concentration of A, the pre-exponential factor, A, which depends on the state of the reactants, T, the temperature, and E a, the activation barrier. With these factors we make a RATE LAW. - Δ[A] = Δ[B] = rate = A exp (-E a /RT ) [A] x = k [A] x aδt bδ t The first three terms A exp (-E a /RT ) combine to make the rate constant, k. Half the problems you do in kinetics use this differential rate expression. Among problems you can do: Calculate the instantaneous rate at any given time: measuring the slope of the tangent line Determining the order of a reaction (the exponent x) using a method of initial rates Calculate k, T, E a, A, [ ] or x given known values. HINT: This third type of problem is simple plug-and-chug except that you need to be able to manipulate the exp term effortlessly. Remember this is done using the inverse relationship ln (exp x) = x 1

2 Integrated Rate Law. You might think the differential rate expression above tells us just about all we need to know about reaction kinetics. Almost. The one thing it can t answer is the following simple but important question: Suppose a certain amount of compound reacts over time; how much is left at some later time? (for example, I have 100 molecules of A which reacts with a rate constant of 2x10-2 sec -1. How much A is left after 1 s?) To work this problem we need to integrate the differential rate expression. Those of you who have had calculus can do this easily. The answers for the three most important reaction orders are shown below. differential rate law order x = 0 order x = 1 order x = 2 - Δ[A] = k aδt - Δ[A] = k [A] 1 aδt - Δ[A] = k [A] 2 aδt integrated rate law [A] = [A o ] - akt ln [A] = ln[a o ] - akt 1/[A] = 1/[A o ] + akt In each case, you can calculate how much is left from starting materials or formed as products given the starting amount, [A o ], the rate constant, k, and the reaction time, t. Reaction half life. As an aside, there is a special form of the integrated rate equation corresponding to when half of the starting material, [A] = 0.5 [A o ], has disappeared. The half-life was an important expression back when people didn t have calculators that could do ln functions, but now we do, so the half life expression is of little value. You can solve for this special case, or you can just use the regular integrated rate equation above. More advanced kinetics topics: Curve Fitting Integrated Rate Equations. It is possible to arrange the integrated rate expressions so they look like straight line functions, y = mx + b. For example, ln[a] = -akt + ln [Ao] y m x b This means you can plot the ln of [A] at different times and get [A o ] from the y-intercept and the rate constant, k, from the slope. Reaction mechanism. The rate law of a reaction does not have to correspond to the stoichiometry of a reaction. If A + B C + D it does not mean that rate = k [A] 1 [B] 1 Instead lots of complicated things might be going on in the form of a reaction mechanism. Maybe A I 1, I 1 I 2, I 2 + B C +D where I 1 and I 2 are reaction intermediates. The reaction order is determined by everything that happens in this multi-step process BEFORE the Rate Determining Step (the slowest step in the reaction.) Thus, If A I 1 is the slowest step, then whatever happens afterward doesn t affect the rate and the reaction rate law is just rate = k[a] 2

3 Kinetic Theories: Every chapter has it theories. This chapter has two. Collision Theory: This theory suggests that sometimes reaction don t occur because even when molecules collide, maybe they don t collide in the right orientation. For example, maybe the δ - part of a molecule needs to bump into the δ + part of another molecule, but instead bumps into the δ -. Instead of a reaction, repulsion occurs instead of a reactive collision. Transition State Theory. This theory suggests that even when molecules collide in the right orientation, they don t have enough energy to overcome an energy barrier to forming an intermediate transition state: A + B B A---B---B A B + B Transition state There is an energy barrier to this transition state called the activation energy, E a, that we saw in the rate law. This energy barrier is the reason I have to light a match to start a combustion reaction like H 2 + O 2. It is also the reason that a catalyst can be added to a reaction to lower a reaction barrier and make a reaction happen faster. An example of this was adding a metal oxide to hydrogen peroxide to make it react faster. Remember that the metal oxide wasn t part of the reaction, it was still there when the reaction ended. It simply made it easier to form the transition state. Combining Arrenhius equations: How does one experimentally calculate the activation energy, Ea? One approach is to combine Arrenhius equations, K 1 = A exp (-E a /RT 1 ) K 2 = A exp (-E a /RT 1 ) combine to yield ln(k 2 /k 1 ) = (E a /R)(1/T 1 1/T 2 ) Experimentally, we can run a reaction at two different temperatures, measure two rate constants and then plot the data to obtain the activation energy, E a, from the slope of the line. 3

4 Kinetics: Thermodynamics let s us down: Okay, we ve finished a three month primer on thermodynamics and you now know how to tell whether a reaction is spontaneous. Just do a ΔG o Gibbs free energy calculation. Okay, let s take our knowledge and put it to good use: Consider the combustion of ethanol: ΔG f o CH 3 CH 2 OH + 7/2 O > 2 CO 2 + 3H 2 O ΔG o rxn = kj Clearly a spontaneous reaction. Except that you all know that ethanol doesn t react in the presence of O 2 or it wouldn t be such a popular beverage. What s going on? Has thermodynamics failed us? Getting over the activation barrier: Now consider what happens when I light a match over some liquid ethanol. Suddenly a reaction starts. After a while we would see that it has gone to completion. But it would take a while until all the ethanol had been combusted to form CO 2. Now consider a case where we have gaseous ethanol in a bottle. After we light a match the reaction is almost explosively fast. What is going on? What Kinetics Tells Us: Remember that thermodynamics can do nothing more than tell us whether things will react and the extent to which they react. It tells us that ethanol and O 2 will react and sure enough they do. But nothing we have learned before today explains the three experiments just shown: 1. Without a match, the reaction doesn t occur at all 2. As a liquid the reaction occurs at a slow rate over the course of minutes. 3. As a gas, the reaction occurs violently in a few seconds. The explanations for these three observations come not from thermodynamics but rather from an understanding of chemical kinetics. 4

5 Chemical kinetics: the study of the rate and mechanism by which a reaction occurs. Chemical rate: The amount of reactant consumed or product formed as a function of time Chemical mechanism: the path by which a reaction occurs. Remember how we stressed over and over about thermodynamics that we neither cared how fast or by what path a reaction occurred? Now you see why, we were just saving those topics for the kinetics chapter. Rate of Reaction: For a reaction aa + bb > cc + dd where the quantities A, B, C, D are concentrations of reactants and products and a,b,c,d are stoichiometric coefficients to balance the reaction, there will be a rate at which the reactants decrease in concentration and products increase in concentration for a particular time interval. This is shown in the concentration vs. time plot below. 5

6 The Rate Equation for the [ ] vs. t plots Can we develop the math to describe this process? Shown below are the differential rate expressions for each of the products and reactants -1 Δ[A] -1 Δ[B] 1 Δ[C] 1 Δ[D] rate = = = = a Δt b Δt c Δt d Δt As Δt decreases, we better define the instantaneous concentration and for a specific time and write the equations replacing Δt with a derivative, dt and Δ[A] with a derivative d[a]. -1 d[a] 1 d[c] rate = = a dt c dt Note that the negative signs for A and B indicate the reactants are decreasing in concentration. Note also that by using the coefficients from the balanced reactions, we can equate the rates for each of the chemical species. Thus we have one rate of reaction and can obtain it from a measurement of any reactant or product. Concentration-Time Plots: Ideally we would have some kind of detector that would allow us to follow the change in concentrations of a reaction as a function of time. We would be able to obtain plots that look like the one below from which at any point in time we would know exactly which species were present in the chemical system. What we could also learn from these plots is the instantaneous rate of reaction. Consider just one of the reaction profiles above for a reactant decreasing in concentration over time. Note that initial the reactant is initially disappearing at a fast rate and that later in the reaction it slows down. If we want, we can get the instantaneous rate by measuring the slope at any point, for example by finding a tangent to the curve. Those of you who are turned on by math may recognize this as the way you were introduced to the concept of derivatives in calculus. 6

7 Mathematically, we could find the rate at any point if we knew the function for the curve and could take the derivative and solve for a particular time. Good news--we will learn how to make a function that fits this curve in a bit. Factors Affecting Reaction Rate: There are several factors that affect how fast a reaction happens; i.e., how steep the slope of the curve is: 1. nature of the reactant 2. concentration of reactants 3. temperature 4. presence of a catalyst. We will examine each of these beginning today with the first two factors. 7

8 Nature of reactants. We have already seen a good example of how the physical state of a reagent affects reaction rate. Remember our ethanol reaction? When we combusted the liquid, the reaction took a while to reach completion. However when we made it into a gas in an enclosed volume, the rate skyrocketed. For the ethanol case, the reason the gas phase reaction went much faster is because the conditions made it possible for a greater number of ethanol molecules per unit time to encounter oxygen molecules. Rule of thumb: In general, the greater the division of sample, either by increasing surface area or exposing the atoms or molecules in the gas phase, the faster the reaction. Rate of reaction and reagent concentration: A rate-law expression relates the rate of a reaction to concentration. For example, note in the example shown in class, the rate of reaction was observed to decrease as the concentration decreased. Rate Law: For a reaction involving reactants A, B,..., the rate is dependent on concentration as described by an equation with the following general form rate = k[a] x [B] y... Here k is the rate constant and x and y are coefficients for the reaction, typically integer values, most commonly 0,1 and 2. The coefficients x and y are NOT the coefficients associated with stoichiometry. Order of a reaction: The order of a reaction is found by summing the coefficients. reaction order = x + y +... Typical values for reaction orders are integers, most commonly 0, 1 and 2. I will be providing a handout and worksheet on all the ways to determine orders of reactions. 8

### 16 Kinetics. CH 302 Kinetics Study Guide (Memorize these two pages, they are all the background you need)

16 Kinetics CH 302 Kinetics Study Guide (Memorize these two pages, they are all the background you need) Reaction Rate: The most important issue in kinetics is a determination of the rate of a reaction

### Lecture 22: The Arrhenius Equation and reaction mechanisms. As we wrap up kinetics we will:

As we wrap up kinetics we will: Lecture 22: The Arrhenius Equation and reaction mechanisms. Briefly summarize the differential and integrated rate law equations for 0, 1 and 2 order reaction Learn how

### Factors That Affect Rates. Factors That Affect Rates. Factors That Affect Rates. Factors That Affect Rates

KINETICS Kinetics Study of the speed or rate of a reaction under various conditions Thermodynamically favorable reactions DO NOT mean fast reactions Some reactions take fraction of a second (explosion)

### Chapter 14 Chemical Kinetics

7/10/003 Chapter 14 Chemical Kinetics 14-1 Rates of Chemical Reactions 14- Reaction Rates and Concentrations 14-3 The Dependence of Concentrations on Time 14-4 Reaction Mechanisms 14-5 Reaction Mechanism

### Chapter 14 Chemical Kinetics

How fast do chemical processes occur? There is an enormous range of time scales. Chapter 14 Chemical Kinetics Kinetics also sheds light on the reaction mechanism (exactly how the reaction occurs). Why

### Chapter 14 Chemical Kinetics

4//004 Chapter 4 Chemical Kinetics 4- Rates of Chemical Reactions 4- Reaction Rates and Concentrations 4-3 The Dependence of Concentrations on Time 4-4 Reaction Mechanisms 4-5 Reaction Mechanism and Rate

### Chapter 11 Rate of Reaction

William L Masterton Cecile N. Hurley http://academic.cengage.com/chemistry/masterton Chapter 11 Rate of Reaction Edward J. Neth University of Connecticut Outline 1. Meaning of reaction rate 2. Reaction

### Chapter 14 Chemical Kinetics

Chapter 14 Chemical Kinetics Factors that Affect Reaction rates Reaction Rates Concentration and Rate The Change of Concentration with Time Temperature and Rate Reactions Mechanisms Catalysis Chemical

### Chapter 14 Chemical Kinetics

Chapter 14 Chemical Kinetics Factors that Affect Reaction rates Reaction Rates Concentration and Rate The Change of Concentration with Time Temperature and Rate Reactions Mechanisms Catalysis Chemical

### CHEMISTRY. Chapter 14 Chemical Kinetics

CHEMISTRY The Central Science 8 th Edition Chapter 14 Kozet YAPSAKLI kinetics is the study of how rapidly chemical reactions occur. rate at which a chemical process occurs. Reaction rates depends on The

### Brown et al, Chemistry, 2nd ed (AUS), Ch. 12:

Kinetics: Contents Brown et al, Chemistry, 2 nd ed (AUS), Ch. 12: Why kinetics? What is kinetics? Factors that Affect Reaction Rates Reaction Rates Concentration and Reaction Rate The Change of Concentration

### Chapter 14: Chemical Kinetics

Chapter 14: Chemical Kinetics NOTE THIS CHAPTER IS #2 TOP TOPICS ON AP EXAM!!! NOT ONLY DO YOU NEED TO FOCUS ON THEORY (and lots of MATH) BUT YOU MUST READ THE FIGURES TOO!!! Ch 14.1 ~ Factors that Affect

### AP CHEMISTRY CHAPTER 12 KINETICS

AP CHEMISTRY CHAPTER 12 KINETICS Thermodynamics tells us if a reaction can occur. Kinetics tells us how quickly the reaction occurs. Some reactions that are thermodynamically feasible are kinetically so

### Ch 13 Chemical Kinetics. Modified by Dr. Cheng-Yu Lai

Ch 13 Chemical Kinetics Modified by Dr. Cheng-Yu Lai Outline 1. Meaning of reaction rate 2. Reaction rate and concentration 3. Writing a Rate Law 4. Reactant concentration and time 5. Reaction rate and

### CHAPTER 12 CHEMICAL KINETICS

5/9/202 CHAPTER 2 CHEMICAL KINETICS CHM52 GCC Kinetics Some chemical reactions occur almost instantaneously, while others are very slow. Chemical Kinetics - study of factors that affect how fast a reaction

### Chapter 14. Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten

Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 14 John D. Bookstaver St. Charles Community College St. Peters, MO 2006, Prentice Hall,

### Chemical Kinetics. Kinetics is the study of how fast chemical reactions occur. There are 4 important factors which affect rates of reactions:

Chemical Kinetics Kinetics is the study of how fast chemical reactions occur. There are 4 important factors which affect rates of reactions: reactant concentration temperature action of catalysts surface

### AP * Chemistry. Kinetics: Integrated Rate Law & Determining Ea. René McCormick

AP * Chemistry Kinetics: Integrated Rate Law & Determining Ea René McCormick *AP is a registered trademark of the College Board, which was not involved in the production of, and does not endorse, this

### How fast reactants turn into products. Usually measured in Molarity per second units. Kinetics

How fast reactants turn into products. Usually measured in Molarity per second units. Kinetics Reaction rated are fractions of a second for fireworks to explode. Reaction Rates takes years for a metal

### AP Chemistry - Notes - Chapter 12 - Kinetics Page 1 of 7 Chapter 12 outline : Chemical kinetics

AP Chemistry - Notes - Chapter 12 - Kinetics Page 1 of 7 Chapter 12 outline : Chemical kinetics A. Chemical Kinetics - chemistry of reaction rates 1. Reaction Rates a. Reaction rate- the change in concentration

### Chemical. Chapter 14. Kinetics. Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E.

Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 14 1 PDF Created with deskpdf PDF www.farq.xyz Writer - Trial :: http://www.docudesk.com

### Chapter 14 Chemical Kinetics

Chapter 14 Chemical Kinetics Learning goals and key skills: Understand the factors that affect the rate of chemical reactions Determine the rate of reaction given time and concentration Relate the rate

### Chapter 13 Kinetics: Rates and Mechanisms of Chemical Reactions

Chapter 13 Kinetics: Rates and Mechanisms of Chemical Reactions 14.1 Focusing on Reaction Rate 14.2 Expressing the Reaction Rate 14.3 The Rate Law and Its Components 14.4 Integrated Rate Laws: Concentration

### Kinetics - Chapter 14. reactions are reactions that will happen - but we can t tell how fast. - the steps by which a reaction takes place.

The study of. Kinetics - Chapter 14 reactions are reactions that will happen - but we can t tell how fast. - the steps by which a reaction takes place. Factors that Affect Rx Rates 1. The more readily

### REACTION KINETICS. Catalysts substances that increase the rates of chemical reactions without being used up. e.g. enzymes.

REACTION KINETICS Study of reaction rates Why? Rates of chemical reactions are primarily controlled by 5 factors: the chemical nature of the reactants 2 the ability of the reactants to come in contact

### Kinetics. Chapter 14. Chemical Kinetics

Lecture Presentation Chapter 14 Yonsei University In kinetics we study the rate at which a chemical process occurs. Besides information about the speed at which reactions occur, kinetics also sheds light

### 14.1 Expressing the Reaction Rate

14.1 Expressing the Reaction Rate Differential Rate and Integrated Rate Laws Fred Omega Garces Chemistry 201 Miramar College 1 Expressing Reaction Rates Outline Kinetics: Intro Factors influencing Reaction

### Reaction Rate. Rate = Conc. of A at t 2 -Conc. of A at t 1. t 2 -t 1. Rate = Δ[A] Δt

Kinetics The study of reaction rates. Spontaneous reactions are reactions that will happen - but we can t tell how fast. Diamond will spontaneously turn to graphite eventually. Reaction mechanism- the

### Outline: Kinetics. Reaction Rates. Rate Laws. Integrated Rate Laws. Half-life. Arrhenius Equation How rate constant changes with T.

Chemical Kinetics Kinetics Studies the rate at which a chemical process occurs. Besides information about the speed at which reactions occur, kinetics also sheds light on the reaction mechanism (exactly

### Lecture Presentation. Chapter 14. Chemical Kinetics. John D. Bookstaver St. Charles Community College Cottleville, MO Pearson Education, Inc.

Lecture Presentation Chapter 14 John D. Bookstaver St. Charles Community College Cottleville, MO In kinetics we study the rate at which a chemical process occurs. Besides information about the speed at

### Lecture 7: Chemical Equilbria--a bit more detail and some additional kinds of problems.

Lecture 7: Chemical Equilbria--a bit more detail and some additional kinds of problems. Lecture Overview: We get even more involved in the details by equilibria by relating G to K relating K c to K p comparing

### Chapter 12. Kinetics. Factors That Affect Reaction Rates. Factors That Affect Reaction Rates. Chemical. Kinetics

PowerPoint to accompany Kinetics Chapter 12 Chemical Kinetics Studies the rate at which a chemical process occurs. Besides information about the speed at which reactions occur, kinetics also sheds light

### Calculations In Chemistry

Calculations In Chemistry Module 27 Kinetics: Rate Laws Module 27 Kinetics: Rate Laws...773 Lesson 27A: Kinetics Fundamentals...771 Lesson 27B: Rate Laws...778 Lesson 27C: Integrated Rate Law --Zero Order...787

### 11/2/ and the not so familiar. Chemical kinetics is the study of how fast reactions take place.

Familiar Kinetics...and the not so familiar Reaction Rates Chemical kinetics is the study of how fast reactions take place. Some happen almost instantaneously, while others can take millions of years.

### Name AP CHEM / / Chapter 12 Outline Chemical Kinetics

Name AP CHEM / / Chapter 12 Outline Chemical Kinetics The area of chemistry that deals with the rate at which reactions occur is called chemical kinetics. One of the goals of chemical kinetics is to understand

### Chemical Kinetics. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chemical Kinetics Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chemical Kinetics Thermodynamics does a reaction take place? Kinetics how fast does a reaction

### Rates of Chemical Reactions

Rates of Chemical Reactions Jim Birk 12-1 Questions for Consideration 1. What conditions affect reaction rates? 2. How do molecular collisions explain chemical reactions? 3. How do concentration, temperature,

### 11/9/2012 CHEMICAL REACTIONS. 1. Will the reaction occur? 2. How far will the reaction proceed? 3. How fast will the reaction occur?

CHEMICAL REACTIONS LECTURE 11: CHEMICAL KINETICS 1. Will the reaction occur? 2. How far will the reaction proceed? 3. How fast will the reaction occur? CHEMICAL REACTIONS C(s, diamond) C(s, graphite) G

### Chemical Kinetics. Chapter 13. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chemical Kinetics Chapter 13 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chemical Kinetics Thermodynamics does a reaction take place? Kinetics how fast does

### Chemical Kinetics and Equilibrium

Chemical Kinetics and Equilibrium Part 1: Kinetics David A. Katz Department of Chemistry Pima Community College Tucson, AZ USA Chemical Kinetics The study of the rates of chemical reactions and how they

### 2/23/2018. Familiar Kinetics. ...and the not so familiar. Chemical kinetics is the study of how fast reactions take place.

CHEMICAL KINETICS & REACTION MECHANISMS Readings, Examples & Problems Petrucci, et al., th ed. Chapter 20 Petrucci, et al., 0 th ed. Chapter 4 Familiar Kinetics...and the not so familiar Reaction Rates

### CHEM 116 Collision Theory and Reaction Mechanisms

CHEM 116 Collision Theory and Reaction Mechanisms Lecture 13 Prof. Sevian Note: If there is anything we do not finish about reaction mechanisms today, that is where we will start on Tuesday with Lecture

### Chapter 11: CHEMICAL KINETICS

Chapter : CHEMICAL KINETICS Study of the rate of a chemical reaction. Reaction Rate (fast or slow?) Igniting gasoline? Making of oil? Iron rusting? We know about speed (miles/hr). Speed Rate = changes

### N H 2 2 NH 3 and 2 NH 3 N H 2

Chemical Equilibrium Notes (Chapter 18) So far, we ve talked about all chemical reactions as if they go only in one direction. However, as with many things in life, chemical reactions can go both in the

### 3: Chemical Kinetics Name: HW 6: Review for Unit Test KEY Class: Date: A Products

3: Chemical Kinetics Name: HW 6: Review for Unit Test KEY Class: Date: Page 1 of 9 AP Multiple Choice Review Questions 1 16 1. The reaction rate is defined as the change in concentration of a reactant

### Chapter 12. Chemical Kinetics

Chapter 12 Chemical Kinetics Chapter 12 Table of Contents 12.1 Reaction Rates 12.2 Rate Laws: An Introduction 12.3 Determining the Form of the Rate Law 12.4 The Integrated Rate Law 12.5 Reaction Mechanisms

### Chemical Kinetics -- Chapter 14

Chemical Kinetics -- Chapter 14 1. Factors that Affect Reaction Rate (a) Nature of the reactants: molecular structure, bond polarity, physical state, etc. heterogeneous reaction: homogeneous reaction:

### Chemistry 201: General Chemistry II - Lecture

Chemistry 20: General Chemistry II - Lecture Dr. Namphol Sinkaset Chapter 5 Study Guide Concepts. rate of reaction: the speed at which reactants disappear and products form. 2. There can only be one numerical

### CHAPTER 13 (MOORE) CHEMICAL KINETICS: RATES AND MECHANISMS OF CHEMICAL REACTIONS

CHAPTER 13 (MOORE) CHEMICAL KINETICS: RATES AND MECHANISMS OF CHEMICAL REACTIONS This chapter deals with reaction rates, or how fast chemical reactions occur. Reaction rates vary greatly some are very

### There is not enough activation energy for the reaction to occur. (Bonds are pretty stable already!)

Study Guide Chemical Kinetics (Chapter 12) AP Chemistry 4 points DUE AT QUIZ (Wednesday., 2/14/18) Topics to be covered on the quiz: chemical kinetics reaction rate instantaneous rate average rate initial

### with increased Lecture Summary #33 Wednesday, December 3, 2014

5. Lecture Summary #33 Wednesday, December 3, 204 Reading for Today: 4.-4.3 in 5 th ed and 3.-3.3 in 4 th ed Reading for Lecture #34: 4.4 & 4.6 in 5 th ed and 3.4 & 3.6 in 4 th ed Topic: Kinetics I. Effect

### Kinetics. Mary J. Bojan Chem Rate: change that occurs in a given interval of time.

Kinetics Rates of reaction average rates instantaneous rates Dependence of rate on concentration rate constant rate laws order of the reaction Dependence of rate on time First order Second order Half-life

### Chemical Kinetics. Rate = [B] t. Rate = [A] t. Chapter 12. Reaction Rates 01. Reaction Rates 02. Reaction Rates 03

Chapter Chemical Kinetics Reaction Rates 0 Reaction Rate: The change in the concentration of a reactant or a product with time (M/s). Reactant Products aa bb Rate = [A] t Rate = [B] t Reaction Rates 0

### Calculating Rates of Substances. Rates of Substances. Ch. 12: Kinetics 12/14/2017. Creative Commons License

Ch. 2: Kinetics An agama lizard basks in the sun. As its body warms, the chemical reactions of its metabolism speed up. Chemistry: OpenStax Creative Commons License Images and tables in this file have

### Chapter 14 Chemical Kinetics

Chapter 14 14.1 Factors that Affect Reaction Rates 14.2 Reaction Rates 14.3 Concentration and Rate Laws 14.4 The Change of Concentration with Time 14.5 Temperature and Rate 14.6 Reaction Mechanisms 14.7

### The first aspects forms the subject matter of chemical equilibrium. The second aspects forms the subject matter of chemical kinetics.

Chemical Kinetics Introduction In a chemical reaction two important aspects are: (a) How far the reaction will go? and (b) How fast the reaction will occur? The first aspects forms the subject matter of

### C H E M I C N E S C I

C H E M I C A L K I N E T S C I 4. Chemical Kinetics Introduction Average and instantaneous Rate of a reaction Express the rate of a reaction in terms of change in concentration Elementary and Complex

### Chem 401 Unit 1 (Kinetics & Thermo) Review

KINETICS 1. For the equation 2 H 2(g) + O 2(g) 2 H 2 O (g) How is the rate of formation of H 2 O mathematically related to the rate of disappearance of O 2? 1 Δ [H2O] Δ[O 2] = 2 Δt Δt 2. Determine the

### Chapter 13 Rates of Reactions

Chapter 13 Rates of Reactions Chemical reactions require varying lengths of time for completion, depending on the characteristics of the reactants and products. The study of the rate, or speed, of a reaction

### Δx Δt. Any average rate can be determined between measurements at 2 points in time.

Chapter 13 Chemical Kinetics Some reaction are faster than others! Chem 210 Jasperse Ch. 13 Handouts 1 Three factors (in addition to the nature of the reacting chemicals themselves ) 1. Concentrations

### Chapter 14: Chemical Kinetics

C h e m i c a l K i n e t i c s P a g e 1 Chapter 14: Chemical Kinetics Homework: Read Chapter 14 Work out sample/practice exercises in the sections, Check for the MasteringChemistry.com assignment and

### What we learn from Chap. 15

Chemical Kinetics Chapter 15 What we learn from Chap. 15 15. The focus of this chapter is the rates and mechanisms of chemical reactions. The applications center around pesticides, beginning with the opening

### where a + b = 2 (this is the general case) These all come from the fact that this is an overall second order reaction.

Chapter 7 Problems Page of 6 //007 7. Hydrolysis of ethyl acetate is as follows: EtAc + OH - Ac - + EtOH. At 5 ºC, the disappearance of OH - is used to determine the extent of the reaction, leading to

### Chemical Kinetics. What Influences Kinetics?

Chemical Kinetics Predictions of likelihood for a reaction to occur have been based on difference in energy between products and reactants: Thermodynamics only compares reactants to products, says nothing

### The first assumption we will put into our theory of kinetics is that two molecules must collide for a reaction to occur between them.

Chapter 18 Chemical Kinetics: Mechanisms In the last chapter we went through the mechanics of how you extract rate constants and order parameters from experimental data. In this chapter we will ge tthe

### Experiment 10 Chemical Kinetics Discovery Lab. Last week in lab. Thermo vs Kinetics. CH 204 Fall 2009 Dr. Brian Anderson

Experiment 10 Chemical Kinetics Discovery Lab CH 204 Fall 2009 Dr. Brian Anderson Last week in lab Click to Titration edit Master curves Changing Third composition level of a weak acid solution as strong

### Chapter 13 - Chemical Kinetics II. Integrated Rate Laws Reaction Rates and Temperature

Chapter 13 - Chemical Kinetics II Integrated Rate Laws Reaction Rates and Temperature Reaction Order - Graphical Picture A ->Products Integrated Rate Laws Zero Order Reactions Rate = k[a] 0 = k (constant

### Collision Theory. Unit 12: Chapter 18. Reaction Rates. Activation Energy. Reversible Reactions. Reversible Reactions. Reaction Rates and Equilibrium

Collision Theory For reactions to occur collisions between particles must have Unit 12: Chapter 18 Reaction Rates and Equilibrium the proper orientation enough kinetic energy See Both In Action 1 2 Activation

### Part One: Reaction Rates. 1. Rates of chemical reactions. (how fast products are formed and/or reactants are used up)

A. Chemical Kinetics deals with: CHAPTER 13: RATES OF REACTION Part One: Reaction Rates 1. Rates of chemical reactions. (how fast products are formed and/or reactants are used up) 2. Mechanisms of chemical

### Chemical Kinetics Ch t ap 1 er

Chemical Kinetics Chapter 13 1 Chemical Kinetics Thermodynamics does a reaction take place? Kinetics how fast does a reaction proceed? Reaction rate is the change in the concentration of a reactant or

### Chapter 12. Chemical Kinetics

Chapter 12 Chemical Kinetics Section 12.1 Reaction Rates Reaction Rate Change in concentration of a reactant or product per unit time. Rate = concentration of A at time t t 2 1 2 1 concentration of A at

### 5.111 Lecture Summary #30 Monday, November 24, 2014

5.111 Lecture Summary #30 Monday, November 24, 2014 Reading for Today: 14.114.5 in 5 th ed and 13.113.5 in 4 th ed. Reading for Lecture #31: 14.6, 17.7 in 5 th ed and 13.6, 17.7 in 4 th ed. Topic: Introduction

### ELEMENTARY CHEMICAL KINETICS

ELEMENTARY CHEMICAL KINETICS EDR Chapter 25... a knowledge of the rate, or time dependence, of chemical change is of critical importance for the successful synthesis of new materials and for the utilization

### Chapter: Chemical Kinetics

Chapter: Chemical Kinetics Rate of Chemical Reaction Question 1 Nitrogen pentaoxide decomposes according to equation: This first order reaction was allowed to proceed at 40 o C and the data below were

### Any thoughts about the chemical reaction type in this video? A. Reaction Rates. Do speed analogy to understand rates in general.

Chemical Kinetics Read Chapter 5: p160-162 Problems: 5.81, 5.85, 5.87, 5.89 We will look at: 1. numerical descriptions of how fast reactions (rxns.) occur 2. the intermediates that form during a rxn (re.

### Chapter 12. Chemical Kinetics

Chapter 12 Chemical Kinetics Section 12.1 Reaction Rates Section 12.1 Reaction Rates Section 12.1 Reaction Rates Section 12.1 Reaction Rates Section 12.1 Reaction Rates Section 12.1 Reaction Rates Section

### Theoretical Models for Chemical Kinetics

Theoretical Models for Chemical Kinetics Thus far we have calculated rate laws, rate constants, reaction orders, etc. based on observations of macroscopic properties, but what is happening at the molecular

### , but bursts into flames in pure oxygen.

Chemical Kinetics Chemical kinetics is concerned with the speeds, or rates of chemical reactions Chemical kinetics is a subject of broad importance. How quickly a medicine can work The balance of ozone

### Ch 13 Rates of Reaction (Chemical Kinetics)

Ch 13 Rates of Reaction (Chemical Kinetics) Reaction Rates and Kinetics - The reaction rate is how fast reactants are converted to products. - Chemical kinetics is the study of reaction rates. Kinetics

### Kinetics CHAPTER IN THIS CHAPTER

CHAPTER 14 Kinetics IN THIS CHAPTER Summary: Thermodynamics often can be used to predict whether a reaction will occur spontaneously, but it gives very little information about the speed at which a reaction

### Chem 116 POGIL Worksheet - Week 6 Kinetics - Part 2

Chem 116 POGIL Worksheet - Week 6 Kinetics - Part 2 Why? A different form of the rate law for a reaction allows us to calculate amounts as a function of time. One variation on this gives us the concept

### Chem 401 Unit 1 (Kinetics & Thermo) Review

KINETICS 1. For the equation 2 H 2(g) + O 2(g) 2 H 2 O (g) How is the rate of formation of H 2 O mathematically related to the rate of disappearance of O 2? 2. Determine the relative reaction rates of

### CHEMISTRY NOTES CHEMICAL KINETICS

CHEMICAL KINETICS Rate of chemical reactions The rate of a reaction tells us how fast the reaction occurs. Let us consider a simple reaction. A + B C + D As the reaction proceeds, the concentration of

### Disorder and Entropy. Disorder and Entropy

Disorder and Entropy Suppose I have 10 particles that can be in one of two states either the blue state or the red state. How many different ways can we arrange those particles among the states? All particles

### Lecture 5: Introduction to Chemical Equilibrium

Lecture 5: Introduction to Chemical Equilibrium This lecture is outside the confines of the textbook development of chemical equilibrium and is intended as a sweeping introduction to chemical equilibrium

Chapter 30 Chemical Kinetics 1 Copyright (c) 2011 by Michael A. Janusa, PhD. All rights reserved. Chemists have three fundamental questions in mind when they study chemical reactions: 1.) What happens?

### Chapter 14, Chemical Kinetics

Last wee we covered the following material: Review Vapor Pressure with two volatile components Chapter 14, Chemical Kinetics (continued) Quizzes next wee will be on Chap 14 through section 14.5. 13.6 Colloids

### Chapter 13 Lecture Lecture Presentation. Chapter 13. Chemical Kinetics. Sherril Soman Grand Valley State University Pearson Education, Inc.

Chapter 13 Lecture Lecture Presentation Chapter 13 Chemical Kinetics Sherril Soman Grand Valley State University Ectotherms Lizards, and other cold-blooded creatures, are ectotherms animals whose body

### Chapter 14. Chemical Kinetics

Chapter 14. Chemical Kinetics Common Student Misconceptions It is possible for mathematics to get in the way of some students understanding of the chemistry of this chapter. Students often assume that

### CHEMISTRY - CLUTCH CH.13 - CHEMICAL KINETICS.

!! www.clutchprep.com CONCEPT: RATES OF CHEMICAL REACTIONS is the study of reaction rates, and tells us the change in concentrations of reactants or products over a period of time. Although a chemical

### Examples of fast and slow reactions

1 of 10 After completing this chapter, you should, at a minimum, be able to do the following. This information can be found in my lecture notes for this and other chapters and also in your text. Correctly

### Chemical Kinetics. System LENGTH: VOLUME MASS Temperature. 1 gal = 4 qt. 1 qt = in 3. 1 L = qt. 1 qt = L

Chemical Kinetics Practice Exam Chemical Kinetics Name (last) (First) Read all questions before you start. Show all work and explain your answers to receive full credit. Report all numerical answers to

### Performance Task: Concentration vs. Time

NAME DATE : Concentration vs. Time Goal of task Target concept: Understand reaction rates in both qualitative and quantitative terms For this task you will be evaluated on your ability to: Construct an

### The rate equation relates mathematically the rate of reaction to the concentration of the reactants.

1.9 Rate Equations Rate Equations The rate equation relates mathematically the rate of reaction to the concentration of the reactants. For the following reaction, aa + bb products, the generalised rate

### Rate law: rate = - [ ]/ t = k [ ] x where x = order. Rate constant = k depends on T (k = Ae -Ea/RT )

Chem 1B Objective 5: Understand factors that determine reaction rate and describe reaction rate with rate law, order, rate constant, and activation energy. Key Ideas: Important in preserving food, curing

### Chapter 16. Rate Laws. The rate law describes the way in which reactant concentration affects reaction rate.

Rate Laws The rate law describes the way in which reactant concentration affects reaction rate. A rate law is the expression that shows how the rate of formation of product depends on the concentration

### Chapter 14 Chemical Kinetics

Chapter 14 Chemical Kinetics Thermodynamics tells us what can happen and how far towards completion a reaction will proceed. Kinetics tells us how fast the reaction will go. Study of rates of reactions

### Chapter 13 Lecture Lecture Presentation. Chapter 13. Chemical Kinetics. Sherril Soman Grand Valley State University Pearson Education, Inc.

Chapter 13 Lecture Lecture Presentation Chapter 13 Chemical Kinetics Sherril Soman Grand Valley State University Ectotherms Lizards, and other cold-blooded creatures, are ectotherms animals whose body