Reaction Mechanisms Most reactions occur in a series of steps

Slides:

Advertisements

Similar presentations

Chemical Kinetics Reaction rate - the change in concentration of reactant or product per unit time.

Advertisements

Chpt 12 - Chemical Kinetics Reaction Rates Rate Laws Reaction Mechanisms Collision Theory Catalysis HW: Chpt 12 - pg , #s Due Fri Jan. 8.

Collision Theory. Reaction Coordinate Diagrams Multistep Reactions.

Chapter 15 Kinetics. Kinetics Deals with the rate of chemical reactions Deals with the rate of chemical reactions Reaction mechanism – steps that a reaction.

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs.  The sum of the elementary steps must.

Chemistry 1011 Slot 51 Chemistry 1011 TOPIC Rate of Reaction TEXT REFERENCE Masterton and Hurley Chapter 11.

Chapter 14.  Physical state of reactants:  Reactants must come in contact with one another in order for a reaction to occur.  Concentration of reactants:

Kinetics Notes part 3 Reaction Mechanisms. REACTION MECHANISMS Chemical reactions involve a sequence of individual bond-making and bond-breaking steps.

Reaction Mechanisms. Chemical Reactions  Glycolosis  C 6 H 12 O NAD ADP + 2 P  2 CH 3 COCOOH + 2 ATP + 2 NADH + 2 H +  This is the way.

Reaction Mechanisms Chapter 12, Section 6. Reaction Mechanisms The sequence of events that describes the actual process by which reactants become products.

Chapter 9 Phenomenological chemical kinetics (empirical/classical) -- experimental aspects § 9.1 Introduction of chemical kinetics.

Chemical Kinetics Rates of Reactions ©2011 University of Illinois Board of Trustees

Chpt 12 - Chemical Kinetics Reaction Rates Rate Laws Reaction Mechanisms Collision Theory Catalysis HW set1: Chpt 12 - pg , # 22, 23, 28 Due Fri.

A Nanoscale View: Elementary Reactions A Nanoscale View: Elementary Reactions Most reactions occur through a series of simple steps or elementary reactions.

N2O2 is detected during the reaction!

The balanced chemical equation provides information about the beginning and end of reaction. The reaction mechanism gives the path of the reaction. Mechanisms.

Reaction Mechanisms. A balanced equation for a chemical reaction indicates the substances present at the start of the reaction and those produced as the.

Collision Theory & Reaction Mechanisms

Kinetics- Partial Notes. BrO Br - +6H +→ 3Br 2 + 3H 2 O Find the rate law and calculate k Experime nt [BrO 3 - ] [Br - ][H + ]Initial Rate Mol/L.

Chpt 12 - Chemical Kinetics Reaction Rates Rate Laws Reaction Mechanisms Collision Theory Catalysis HW set1: Chpt 12 - pg , # 22, 23, 28 Due Jan.

Reaction Mechanisms A balanced equation tells us the reactants and products, but does not tell us how the reactants became products. Vocabulary: 1.Reaction.

Chapter 9 Phenomenological chemical kinetics (empirical/classical) -- experimental aspects § 9.1 Introduction of chemical kinetics.

Reaction Mechanism Chapter 14 part V

© 2009, Prentice-Hall, Inc. Reaction Mechanisms The sequence of events that describes the actual process by which reactants become products is called the.

Rate Mechanisms The Basics. Reaction Mechanisms O The series of steps that actually occur in a chemical reaction. O Kinetics can tell us something about.

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs.  The sum of the elementary steps must.

Reaction Mechanism. l Process by which a reaction occurs l Reaction occurring in a single event or step its called an elementary reaction l Total reaction.

WARM UP List 3 things you can do to a chemical reaction to increase the rate.

Chapter 12 - Kinetics DE Chemistry Dr. Walker.

Study of Reaction Rates

Rate Expression and reaction mechanism

CHE1031 Lecture 10: Reaction kinetics

Reaction Mechanisms -Catalysis

Chapter 14: Chemical Kinetics

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs. The sum of the elementary steps must give.

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs. The sum of the elementary steps must give.

Reaction Mechanisms.

Reaction Mechanisms Even though a balanced chemical equation may give the ultimate result of a reaction, what actually happens in the reaction may take.

Chemical Kinetics Unit 10 – Chapter 12.

Kinetics Reaction Mechanisms

Reaction Mechanism.

Reaction Mechanisms Chemical Kinetics-5.

Lecture 1405 Reaction Mechanism and Catalysis

Reaction Mechanisms A reaction mechanism is a sequence of molecular events, or reaction steps, that defines the pathway from reactants to products.

WARM UP The rate constant for the 2nd order reaction

Reaction Mechanisms and their relationship to Rate Laws

Draw a Circle Draw a Star Draw a Smiley Face

Rates of Reactions Chapter 6

Reaction Mechanisms.

AP Chem Get Integrated Rate Law HW checked

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs. The sum of the elementary steps must give.

Reaction Mechanisms Elementary Steps Phenomenon Examples Rate Law

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs. The sum of the elementary steps must give.

Reaction Mechanisms.

Factors that Affect Reaction Rate Constant

Reaction mechanism Most reactions occur in a series of steps. Most you don’t see. The reaction mechanism is these series of steps.

Reaction Mechanism The reaction mechanism is the series of elementary steps by which a chemical reaction occurs. The sum of the elementary steps must give.

Reaction Mechanism Most chemical reactions occur by a series of elementary steps. An intermediate is formed in one step and used up in a subsequent step.

Review: If A + B  C & we know the reaction is first order in A and fourth order overall, what reaction order is B? [A]1[B]? [A][B]3.

Reaction Mechanisms Most chemical reactions occur by a series of steps called the reaction mechanism. The overall progress of a chemical reaction can be.

Reaction Pathways.

Announcements Welcome back!

Kinetics Chapter 14.

Chemical Kinetics Lesson 2

12.6 Reaction Mechanisms Discuss #11

Reaction Mechanisms.

Reaction Mechanism Chapter 14 part V

Reaction Mechanisms The sequence of events that describes the actual process by which reactants become products is called the reaction mechanism. Reactions.

Ch11. Integrated rate laws and reaction mechanisms

AP Chem Get Integrated Rate Law HW checked Important Dates:

Presentation transcript:

Reaction Mechanisms Most reactions occur in a series of steps Some products of a first step are used up as reactants in a second step and are not seen in an overall reaction (intermediate) Individual reactions are called elementary steps TWO REQUIREMENTS

Molecularity Deals with the number of species colliding when a reaction happens UNImolecular: one molecule = first order BImolecular: two molecules/species = second order TERmolecular: three species = third order

Elementary Steps Requirements Sum of elementary steps must give the overall balanced equation for the reaction Mechanism must agree with the experimentally determined rate law

Rate-Determining Step Helps confirm the #2 from the last slide The intermediate step that is much slower than the other steps This slower step determines the rate law used in calculations After determining the rate law, the mechanism can be hypothesized

Example 2NO + 2H2 -> 2H2O + N2 Rate = k[NO2]2[H2] Mechanism: NO + H2 -> N + H2O (slow) N + NO -> N2O (fast) N2O + H2 -> N2 + H2O (fast) Is this mechanism consistent with the observed rate law? Answer: (part 1) yes, (part 2) no

Example #2 2NO + 2H2 -> 2H2O + N2 Rate = k[NO2]2[H2] Mechanism: NO + H2 <-> N + H2O (fast, with equal rates) N + NO -> N2O (slow) N2O + H2 -> N2 + H2O (fast) Is this mechanism consistent with the observed rate law? Answer: (part 1) yes, (part 2) no