Part One: Reaction Rates. 1. Rates of chemical reactions. (how fast products are formed and/or reactants are used up)
|
|
- Kathryn George
- 5 years ago
- Views:
Transcription
1 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 reactions. (steps by which they occur) B. Importance: 1. Even though a reaction is thermodynamically favorable it may not occur at all if it is kinetically very slow. C(diamond) + O 2 (g) CO 2 (g) ΔG = -397 kj/mol Diamonds combine with O 2 in air so slowly that to all purposes, not at all, even though such a reaction would proceed downhill in free energy. 2. CH 4 + 2O 2 CO 2 + 2H 2 O, burning of natural gas at high T, is kinetically very rapid as well as being thermodynamically favorable. C. Factors affecting the rate of reaction: 1. The Physical State of the Reactants. a. Rate depends on surface area of contact between the reactants. b. Gases typically react faster than solids or liquids because they more intimately mix and mix faster. c. Finely divided powders or aerosols suspended in air can react explosively because of large surface area exposed. (Exploding grain elevators.) 2. Concentrations of Reactants - the Rate Law. a. Collisions per second between reactant species is greater at higher concentration. b. Dependence of Rate on Concentrations is expressed in the Rate Law. Chapter 13 Page 1
2 c. A rate law expression takes the form: Rate = k[a] x [B] y... d. Expresses how rate varies with concentrations of species present. 3. Temperature: a. Reactions run faster at higher temperatures. 4. Presence of Catalysts. a. A catalyst is a substance that increases the rate of reaction without being consumed by the reaction. b. Example: MnO 2 catalyzes the decomposition of H 2 O 2. D. Definition of Rate. (Section 13.1) 1. Rate loosely is amount of product formed or reactant consumed per unit time. 2. Consider hypothetical reaction: aa + bb cc + dd 3. Rate defined in terms of rate of growth or loss of concentrations [ ] of species: Rate + 1 Δ[ C] = 1 c Δt c Δ[ C] = rate of formation of C Δt Alternatively: [A], [B], [C], [D] increase of C conc. short interval of time Rate = + 1 d Δ[ D] Δt or Rate = 1 a Δ[ A] Δt or Rate = 1 b Δ B [ ] Δt Chapter 13 Page 2
3 4. Analogy: 2 bread slices + 3 sardines + 1 pickle 1 sandwich Rate = Δ [ sandwiches ] = 1 Δt 2 Δ[ bread] Δt etc. 5. The Rate changes with time, in general: H 2 (g) + 2ICl(g) I 2 (g) + 2HCl(g) E. Experimental Determination of the Rate. (Section 13.2) 1. One must be able to measure the concentration of at least one of the reactants or products during the course of the reaction. 2. For slow reactions, one could withdraw samples and analyze them during reaction. 3. More conveniently, one could monitor a physical property of the sample which depends on the concentration of one of the reactants. Example: the absorption of light by one of the species measured by spectroscopy. Through Beers Law, we know that Absorbance concentration at a fixed wavelength. F. Dependence of Rate on Concentrations of Reactants - the Rate Law. (Section 13.3) 1. A rate law expression takes the form: Rate = k[a] x [B] y... Chapter 13 Page 3
4 2. Expresses how rate varies with concentrations of species present. 3. k = rate constant. 4. Powers x and y bear no necessary relationship with balancing coefficients but do depend on the mechanism of the reaction. Example: Rate of one-car accidents = k[cars] 1 Rate of two-car accidents = k [cars] 2 Rate of one-car accidents is said to be 1st-order with respect to concentrations of cars. Rate of two-car accidents is 2nd-order with respect to concentrations of cars. 5. Suppose you found that: Rate = k[h 2 O 2 ][I - ] Reaction is 1st-order with respect to H 2 O 2 1st-order with respect to I - and 2nd-order overall 6. Units of k depend on overall order. 7. k is independent of time, is independent of concentrations, but varies with T and presence of catalyst. G. Experimental Determination of Rate Law. (Section 13.3) 1. Method of initial rates: measure rate at beginning of reaction, when all concentrations are known repeat measurement, vary initial concentration on one species, holding the others fixed 2. Example: The iodine clock reaction at a given temperature. Rate depends on concentration of three species: Rate = k[io 3 - ] a [I - ] b [H + ] c Need to discover the exponents a, b, and c by experiment. Chapter 13 Page 4
5 Initial concentrations (M) Run Initial Rate [IO 3 - ]0 [I - ] 0 [H + ] x 10-5 M s x x x Find the rate law and the rate constant: First, compare Run 1 and Run 2. What changed? Only [IO 3 ] o It doubled and the rate doubled, therefore a = 1 Next, compare Run 1 and Run 3. What changed? Only [I - ] o It doubled and the rate quadrupled, therefore b=2 By comparing Run 1 and 4, we find that c=2 Therefore the Rate Law must be: - - Rate = k[io 3 ][I ] 2 [H + ] 2 Pick one run to solve for k: k = M s 1 ( 0.10M ) 0.10M ( ) 2 ( 0.10M ) = 2.00 M 4 s 1 2 H. Change of Concentrations with Time - Integrated Rate Laws. (Section 13.4) 1. Can solve for [reactant] as function of time if rate law known. 2. This generates an integrated rate equation = equation that relates concentration of species to its initial concentration and time elapsed t. 3. Can also determine t 1 2 = half-life of a reactant = time required for half of initial amount of reactant to be used up. Chapter 13 Page 5
6 4. First-Order Reactions: of the general form aa products Rate = 1 a Δ[ A] Δt = k[a] By integration of the above equation, we obtain the integrated first order rate law, which can be rearranged in a number of forms: [A] = [A] o e -akt [ A] A [ ] o = e akt ln [ A] = -akt A [ ] o ln [ A] o = +akt [ A] [ A] log o 10 = [ A] akt if [A] o, k, and t are known, can solve for [A]; usually a = Problem: The initial concentration of reactant species A in the 1st order reaction: A B is 2.0 M. What is the concentration after 10 seconds if the rate constant k = 0.30 s -1? [A] = [A] o e -akt a = 1, k = 0.30 s -1, t = 10 s, [A] o = 2.0 M [A] = 2.0 M e s-1 10 s = 2.0 M x 4.97 x 10-2 = 9.95 x 10-2 M =.0995 M 6. Derive relation of t 12 to k for 1st order reaction. Chapter 13 Page 6
7 Suppose t elapsed = t 12 Then [A] = 1 2 [A] o t 1 2 = ln 2 ak ln [ A] o [ ] o 1 A 2 = akt 12 ; ln 2 = akt Special Property of 1st Order Reactions: t 1 2 is a constant. Thus if concentration goes to 1 2 during first half-life, it goes to 1 4 in 2nd half-life, to 1 8 in 3rd half-life. Plot: Suppose [A] o = 1 M, t 1 2 = 10 seconds. 8. Radioactive isotope concentration decays by 1st order kinetics. 9. Since [A] = [A] o e -akt intercept b = ln[a] o ln [A] = ln [A] o - akt y = b + m x ln [A] slope = -ak straight line t 10. Second-Order Reactions having a rate law of form aa products 1 Rate - k[a] [ A] 1 2 = akt [ A] o Chapter 13 Page 7
8 Plot: t 1 2 = 1 ak A [ ] o does depend on [A] o I. Collision Theory of Reaction Rates. (Section 13.5) 1. Helps to expose other factors influencing rate: temperature catalysts 2. Collision theory = a. reactants must collide before they can react. b. only some of the collisions are effective in producing products: must have correct orientation (see Figure below) Figure Chapter 13 Page 8
9 must have sufficient energy (see Figure 13.13) Figure Rate = (collision frequency) x (energy factor) x (orientation factor) determined by conc., kinetic energies sizes of particles of molecules enter here 4. Energy factor = e E a RT where E a = activation energy Chapter 13 Page 9
10 5. Yields Rate Expression: Rate = A e E a RT (concentrations) where: A contains info on the orientation, size of particles e E a RT is the energy factor Rate constant is then identified as: (Section 13.6) k = A e E a RT (Arrhenius Equation) Says that rate constant, and hence the rate, depends exponentially on the T: k as T A = Arrhenius pre-exponential factor, called also the frequency factor ln k = ln A - E a RT 6. Another form of Arrhenius equation for comparing k at two T s: ln k 2 = E a k 1 R 1 1 T 1 T 2 J. Transition State Theory. (More generalized theory) 1. Reactants must pass through a short-lived, high energy intermediate state, called the transition state. Chapter 13 Page 10
11 2. Theory uses statistical arguments to calculate the concentration of species in this state: Rate = frequency factor x [transition state] 3. Result comes out virtually same as collision theory but can be applied to a much wider variety of reactions. Part Two: Reaction Mechanisms A. Relationship Between Reaction Mechanism and Rate Law. (Section 13.7) 1. Mechanism = step-by-step pathway by which reaction occurs. 2. Mechanism = series of elementary reaction steps. Example: decomposition of N2O5 2 N2O5 4 NO2 + O2 Mechanism: Figure Chapter 13 Page 11
12 3. For any single elementary step, the rate is proportional to the product of concentrations of each reactant molecule: A B + C Rate = k[a] A + B C Rate = k[a][b] unimolecular elementary rxn bimolecular elementary rxn 4. Rxn is never faster than its slowest step, called the rate-determining step. (i.e. the bottleneck ) 5. Example #1. Overall reaction: NO 2 (g) + CO(g) NO(g) + CO 2 (g) Experimentally found that: Rate = k[no 2 ] 2 What mechanism would be consistent with this observation? Consider reaction progressing by TWO elementary steps: (1) NO 2 + NO 2 N 2 O 4 (slow) (2) N 2 O 4 + CO NO + CO 2 + NO 2 (fast) NO 2 + CO NO + CO 2 (overall) Rate (step 1) = k[no 2 ][NO 2 ] = k[no 2 ] 2 Rate (step 2) = k[n 2 O 4 ][CO] But step 1 is slow, so it limits the rate. Rate = k[no 2 ] 2 Note that this mechanism proposed existence of reaction intermediate N 2 O 4. Other mechanisms can be proposed which also yield the correct rate law. Therefore, simply finding a mechanism which gives the correct rate law does not guarantee that this is the correct mechanism. Other mechanisms may be proposed that might also predict the same rate law. We can only eliminate inconsistent mechanisms, never prove the correct one. Chapter 13 Page 12
13 6. Example #2. Overall reaction: 2 NO(g) + Br 2 (g) 2 NOBr(s) Observed rate law: Rate = k[no] 2 [Br 2 ] Proposed mechanism: A single step involving simultaneous collision of 3 molecules. NO(g) + NO(g) + Br 2 (g) 2 NOBr(s) This immediately produces the observed rate law. However, likelihood of ternary collision is small. Another proposed mechanism: (1) NO + Br 2 NOBr 2 (fast, equilibrium) (2) NOBr 2 + NO 2 NOBr (slow) Since (2) is slow, it is rate-determining, so: Rate = k 2 [NOBr 2 ][NO] But NOBr 2 is a transient intermediate species, so [NOBr 2 ] needs to be written in terms of conc. of other species. Since (1) is in equilibrium: forward rate = reverse rate k 1 f [ NO] [ Br 2 ] = k 1r [ NOBr 2 ] and [ NOBr 2 ] = k 1 f k 1r Substituting back in: k 1 f Rate = k 2 k 1r [ NO] [ Br 2 ] NO [ ] = k[no] 2 [Br 2 ] [ NO] [ Br 2 ] This is consistent with the observed rate law, so this mechanism is plausible. Chapter 13 Page 13
14 7. A generalization can be made: The experimentally determined reaction orders indicate the number of molecules of those reactants involved in; (1) the slow step only, if it occurs first, or (2) the slow step and any fast equilibrium steps preceding the slow step. B. Catalysis. (Section 13.9) 1. Catalyst =substance that increase the rate of a given reaction without being used up by the reaction. 2. They operate by allowing reactions to occur by alternative pathways with lower activation energies. Figure Since rate constant depends on activation energy E a as follows: k = A e -E a RT if E a e -E a RT k rate 4. Two categories of catalysts: Chapter 13 Page 14
15 a. homogeneous - exists in the same phase as the reactants. b. heterogeneous - exists in different phase than reactants. 5. Example of homogeneous catalysis. Strong acids (i.e. the H + ion) catalyze hydrolysis of esters. Overall: Postulated mechanism: 6. Example of heterogeneous catalysis (contact catalyst). a. First step is usually adsorption of reactant on a solid surface (which acts as the catalyst): Figure Chapter 13 Page 15
16 b. Catalytic converters work this way, catalyzing oxidation of unburned fuel and CO. Figure Pt 2CO( g) + O 2 ( g) NiO 2CO 2 ( g) This reaction without catalysts would take thousands of years. 7. Enzymes are protein molecules which serve as catalysts for biochemical rxns. Figure Chapter 13 Page 16
17 8. CFC s (Chlorofluorocarbons) are thought to decompose in the upper atmosphere into ClO radicals that catalyze the decomposition of the ozone layer. 9. CFC s have been banned from many uses. (refrigerants, aerosol spray propellants) Chapter 13 Page 17
18 NOTES: Chapter 13 Page 18
Part One: Reaction Rates. 1. Even though a reaction is thermodynamically favorable it may not occur at all if it is kinetically very slow.
CHAPTER 13: RATES OF REACTION Part One: Reaction Rates A. Chemical Kinetics deals with: 1. 2. B. Importance: 1. Even though a reaction is thermodynamically favorable it may not occur at all if it is kinetically
More informationCh 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
More informationHow 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
More informationFactors 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)
More informationChemical 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
More informationChapter 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
More informationCHAPTER 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
More informationChapter 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
More informationAP 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
More informationChapter 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
More informationKinetics. 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
More informationChemical 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
More informationKinetics - 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
More informationChapter 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
More informationChapter 12 - Chemical Kinetics
Chapter 1 - Chemical Kinetics 1.1 Reaction Rates A. Chemical kinetics 1. Study of the speed with which reactants are converted to products B. Reaction Rate 1. The change in concentration of a reactant
More informationTheoretical 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
More informationChapter 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
More informationName 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
More informationChemical 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
More informationChapter 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
More informationChapter 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
More informationChapter 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
More informationAP 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
More informationReaction 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
More informationName: UNIT 5 KINETICS NOTES PACEKT #: KINETICS NOTES PART C
KINETICS NOTES PART C IV) Section 14.4 The Change of Concentration with Time A) Integrated Rate Law: shows how the concentration of the reactant(s) varies with time 1) [A]0 is the initial concentration
More informationChapter 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
More informationAP Chem Chapter 14 Study Questions
Class: Date: AP Chem Chapter 14 Study Questions 1. A burning splint will burn more vigorously in pure oxygen than in air because a. oxygen is a reactant in combustion and concentration of oxygen is higher
More information11/2/ 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.
More informationCHEMISTRY. 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
More informationChemical 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
More informationChapter 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
More informationCHAPTER 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
More informationChapter 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
More informationChemical Kinetics. What quantities do we study regarding chemical reactions? 15 Chemical Kinetics
Chemical Kinetics Chemical kinetics: the study of reaction rate, a quantity conditions affecting it, the molecular events during a chemical reaction (mechanism), and presence of other components (catalysis).
More informationChapter 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
More informationBrown 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
More informationCh part 2.notebook. November 30, Ch 12 Kinetics Notes part 2
Ch 12 Kinetics Notes part 2 IV. The Effect of Temperature on Reaction Rate Revisited A. According to the kinetic molecular theory of gases, the average kinetic energy of a collection of gas molecules is
More informationLecture Presentation. Chapter 14. James F. Kirby Quinnipiac University Hamden, CT. Chemical Kinetics Pearson Education, Inc.
Lecture Presentation Chapter 14 James F. Kirby Quinnipiac University Hamden, CT In chemical kinetics we study the rate (or speed) at which a chemical process occurs. Besides information about the speed
More informationChapter 14. Chemical Kinetics
Chapter 14. Chemical Kinetics 14.1 Factors that Affect Reaction Rates The speed at which a chemical reaction occurs is the reaction rate. Chemical kinetics is the study of how fast chemical reactions occur.
More informationChemical 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
More informationChapter 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
More informationKinetics is the study of of chemical reactions and the by which they occur.
Kinetics is the study of of chemical reactions and the by which they occur. tells us if a reaction can occur while tells us how quickly the reaction occurs some reactions that are thermodynamically feasible
More informationChapter 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
More informationKinetics 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
More informationChapter 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
More informationChemistry 102 Chapter 14 CHEMICAL KINETICS. The study of the Rates of Chemical Reactions: how fast do chemical reactions proceed to form products
CHEMICAL KINETICS Chemical Kinetics: The study of the Rates of Chemical Reactions: how fast do chemical reactions proceed to form products The study of Reaction Mechanisms: the steps involved in the change
More informationChemical Kinetics AP Chemistry Lecture Outline
Chemical Kinetics AP Chemistry Lecture Outline Name: Factors that govern rates of reactions. Generally... (1)...as the concentration of reactants increases, rate (2)...as temperature increases, rate (3)...with
More informationKinetics. 1. Consider the following reaction: 3 A 2 B How is the average rate of appearance of B related to the average rate of disappearance of A?
Kinetics 1. Consider the following reaction: 3 A 2 B How is the average rate of appearance of B related to the average rate of disappearance of A? A. [A]/ t = [B]/ t B. [A]/ t = (2/3)( [B]/ t) C. [A]/
More informationChapter 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
More informationChemical Kinetics. Reaction Rate. Reaction Rate. Reaction Rate. Reaction Rate. Chemistry: The Molecular Science Moore, Stanitski and Jurs
Chemical Kinetics Chemistry: The Molecular Science Moore, Stanitski and Jurs The study of speeds of reactions and the nanoscale pathways or rearrangements by which atoms and molecules are transformed to
More informationLecture (3) 1. Reaction Rates. 2 NO 2 (g) 2 NO(g) + O 2 (g) Summary:
Summary: Lecture (3) The expressions of rate of reaction and types of rates; Stoichiometric relationships between the rates of appearance or disappearance of components in a given reaction; Determination
More informationCh 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
More informationCHEMISTRY. Chapter 13. Chapter Outline. Factors Affecting Rate
CHEMISTRY Fifth Edition Gilbert Kirss Foster Bretz Davies Chapter 3 Chemical Kinetics: Reactions in the Atmosphere Chemistry, 5 th Edition Copyright 207, W. W. Norton & Company Chapter Outline 3.4 Reaction
More informationShroud of Turin. Chemical Kinetics. Reaction Rates. Reaction Rates. Reaction Rates. Chemical Kinetics: The Rates of Chemical Reactions
Page III-12-1 / Chapter Twelve Lecture Notes Chemical Kinetics: The Rates of Chemical Reactions Chapter 12 Chemistry 222 Professor Michael Russell Shroud of Turin Shroud of Jesus?!? Fake or Real? Explored
More informationLecture 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
More informationChapter 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
More information11/9/2012 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
More informationUnit 12: Chemical Kinetics
Unit 12: Chemical Kinetics Author: S. Michalek Introductory Resources: Zumdahl v. 5 Chapter 12 Main Ideas: Integrated rate laws Half life reactions Reaction Mechanisms Model for chemical kinetics Catalysis
More informationChemical Kinetics. Reaction Rate. Reaction Rate. Reaction Rate. Reaction Rate. Chapter 13: Chemical Kinetics: Rates of Reactions
Chemical Kinetics The study of speeds of reactions and the nanoscale pathways or rearrangements by which atoms and molecules are transformed to products Chapter 3: Chemical Kinetics: Rates of Reactions
More information14.1 Factors That Affect Reaction Rates
14.1 Factors That Affect Reaction Rates 1) 2) 3) 4) 14.2 Reaction Rates How does increasing the partial pressures of the reactive components of a gaseous mixture affect the rate at which the compounds
More informationWhat 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
More informationC 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
More informationChapter 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
More informationChapter 14: Chemical Kinetics II. Chem 102 Dr. Eloranta
Chapter 14: Chemical Kinetics II Chem 102 Dr. Eloranta Rate Laws If you are familiar with calculus Experiments would allow you to determine the reaction order and rate constant, but what if you wanted
More informationREACTION 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
More informationRates 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,
More informationChemical 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
More informationCHEMICAL KINETICS. (Part II)
Chapter 14 CHEMICAL KINETICS (Part II) Dr. Al Saadi 1 Reaction Mechanism Most reactions occur in a series of steps. The balancedequation equation gives information about the initial reactants and the final
More informationChapter Chemical Kinetics
CHM 51 Chapter 13.5-13.7 Chemical Kinetics Graphical Determination of the Rate Law for A Product Plots of [A] versus time, ln[a] versus time, and 1/[A] versus time allow determination of whether a reaction
More informationCalculating 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
More informationChapter 14. Chemical Kinetics
14.1 Factors that Affect Reaction Rates Chemical kinetics = the study of how fast chemical reactions occur. Factors which affect rates of reactions: Physical state of the reactants. Concentration of the
More informationChemical 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
More informationCHAPTER 10 CHEMICAL KINETICS
CHAPTER 10 CHEMICAL KINETICS Introduction To this point in our study of chemistry, we have been concerned only with the composition of the equilibrium mixture, not the length of time required to obtain
More informationChemical. 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
More informationChemical 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:
More informationTOPIC 6: Chemical kinetics
TOPIC 6: Chemical kinetics Reaction rates Reaction rate laws Integrated reaction rate laws Reaction mechanism Kinetic theories Arrhenius law Catalysis Enzimatic catalysis Fuente: Cedre http://loincognito.-iles.wordpress.com/202/04/titanic-
More information3: 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
More informationChapter 30. Chemical Kinetics. Copyright (c) 2011 by Michael A. Janusa, PhD. All rights reserved.
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?
More informationChapter 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
More informationChemical Kinetics. Topic 7
Chemical Kinetics Topic 7 Corrosion of Titanic wrec Casón shipwrec 2Fe(s) + 3/2O 2 (g) + H 2 O --> Fe 2 O 3.H 2 O(s) 2Na(s) + 2H 2 O --> 2NaOH(aq) + H 2 (g) Two examples of the time needed for a chemical
More information2/23/2018. 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
More informationReaction Kinetics. Reaction kinetics is the study of the rates of reactions and the factors which affect the rates. Hebden Unit 1 (page 1 34)
Hebden Unit 1 (page 1 34) Reaction kinetics is the study of the rates of reactions and the factors which affect the rates. 2 1 What are kinetic studies good for? 3 How to speed up: 1. Paint drying 2. Setting
More informationHomework #4 Chapter 15 Chemical Kinetics. Therefore, k depends only on temperature. The rate of the reaction depends on all of these items (a d).
Homework #4 Chapter 5 Chemical Kinetics 8. Arrhenius Equation Therefore, k depends only on temperature. The rate of the reaction depends on all of these items (a d). 4. a) d) b) c) e) 5. Rate has units
More informationYes. Yes. Yes. Experimental data: the concentration of a reactant or product measured as a function of time. Graph of conc. vs.
Experimental data: the concentration of a reactant or product measured as a function of time Graph of conc. vs. time Is graph a straigh t line? No Graph of ln[conc.] vs. time Yes System is zero order Is
More informationProperties of Solutions and Kinetics. Unit 8 Chapters 4.5, 13 and 14
Properties of Solutions and Kinetics Unit 8 Chapters 4.5, 13 and 14 Unit 8.1: Solutions Chapters 4.5, 13.1-13.4 Classification of Matter Solutions are homogeneous mixtures Solute A solute is the dissolved
More informationUnit #10. Chemical Kinetics
Unit #10 Chemical Kinetics Zumdahl Chapter 12 College Board Performance Objectives: Express the rate of a reaction in terms of changes in the concentration of a reactant or a product per time. Understand
More informationThe 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
More informationReaction Rates and Chemical Equilibrium
Reaction Rates and Chemical Equilibrium 12-1 12.1 Reaction Rates a measure of how fast a reaction occurs. Some reactions are inherently fast and some are slow 12-2 12.2 Collision Theory In order for a
More informationReaction Rates and Chemical Equilibrium
Reaction Rates and Chemical Equilibrium : 12-1 12.1 Reaction Rates : a measure of how fast a reaction occurs. Some reactions are inherently fast and some are slow: 12-2 1 12.2 Collision Theory In order
More informationAnnouncement. CHEM 1001N quizzes
Announcement CHEM 1001N quizzes Surnames A - M: Stedman Lecture Hall D Surnames N - Z: Accolade East 001 Those who will be writing in Accolade East 001 should go and find that room NOW because they will
More informationChapter 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 reaction orders may be determined
More informationthe following equilibrium constants. Label the thermodynamic and kinetic regions.
REACTION RATES 1. Distinguish between kinetic and thermodynamic regions of a reaction. 2. How does an increase in pressure affect the rate of a gas-phase reaction? What effect on the rate would doubling
More informationChapter 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
More informationΔx 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
More informationCHEM Dr. Babb s Sections Lecture Problem Sheets
CHEM 116 - Dr. Babb s Sections Lecture Problem Sheets Kinetics: Integrated Form of Rate Law 61. Give the integrated form of a zeroth order reaction. Define the half-life and find the halflife for a general
More informationChem 116 POGIL Worksheet - Week 6 Kinetics - Concluded
Chem 116 POGIL Worksheet - Week 6 Kinetics - Concluded Why? The half-life idea is most useful in conjunction with first-order kinetics, which include many chemical reactions and all nuclear decay processes.
More informationExamples 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
More informationAP CHEMISTRY NOTES 7-1 KINETICS AND RATE LAW AN INTRODUCTION
AP CHEMISTRY NOTES 7-1 KINETICS AND RATE LAW AN INTRODUCTION CHEMICAL KINETICS the study of rates of chemical reactions and the mechanisms by which they occur FACTORS WHICH AFFECT REACTION RATES 1. Nature
More informationOutline: 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
More informationChapter 14. Chemical Kinetics
Sample Exercise 14.1 (p. 578) For the reaction pictured at the bottom of the previous page, calculate the average rate at which A disappears over the time interval from 20 s to 40 s. (1.2 x 10-2 M/s) Practice
More information