1. Kinetics CHEM 210 Spring 2014 Dr. Vilchiz

2. What is Kinetics? One of the three main branches of Physical Chemistry It is responsible for studies in rate of reactions and reaction mechanisms It is governed by three complementing theories ◦ Kinetic Molecular Theory- Atomic Motion ◦ Collision Theory- Chemical Reactions ◦ Transition State Theory-Activated Complex

3. The 1800’s 1850- (Wilhelmy) earliest study on rates. Rate of inversion of glucose & fructose in the presence of acid. 1864- (Guldberg & Waage) law of mass action 1865- (Harcourt & Esson) time integrated rate laws & temperature dependence 1884- van’t Hoff Equation 1887- (Ostwald) Reaction order & catalysis and half-life 1889- Arrhenius Equation

4. The 1900’s 1913- (Chapman & Bodenstein) steady- state approximation 1917- (Trautz & Lewis) Collisional Theory 1920’s- (Langmuir & Hinshelwood) Heterogeneous reactions 1935- (Eyring) Transition State Theory

5. Ludwig Wilhelmy Published the first quantitative study of chemical kinetics. Studied the acid-catalyzed conversion of sucrose into a 1:1 mixture of glucose and fructose and measured by polarimetry ◦ The reaction rate depended on the [sucrose] and [H + ]

6. Cato Max Guldberg & Peter Waage Introduced the notion of the Law of Mass Action ◦ Based on the work on reversible reactions by Claude Berthollet ◦ Predicts the behavior of solutions in a dynamic equilibrium  Relate kinetics to thermodynamics  Measured the composition of a mixture at equilibrium  Introduced the notion of a dynamic equilibrium

7. Augustus George Vernon Harcourt and William Esson Studied the rate of reaction in the Iodine- Clock reaction and determined that the rate of the reaction depended on the [R] and determined the change as a function of time. Video Clock Reaction

8. Jacobs Henricus van’t Hoff Independently studies the [ ] dependence of reactions and changes with time 1 st recipient of the NP in Chemistry 1/3 Father of Modern Physical Chemistry ◦ Published “Etudes de Dynamique Chimique”  Describes the method of determining reaction orders graphically ◦ Demonstrates the similarity between dilute solutions and gases ◦ van’t Hoff eq.

9. Wilhelm Ostwald NP Chemistry 1909 1/3 father of Modern Physical Chemistry ◦ Used Catalysis to determine Acid Strength ◦ Studied Transport Phenomena in liquids  Ostwald Viscometer  Viscosity of Liquids

10. Svante Arrhenius A Physicist by training… a Chemist at heart… NP Chemistry 1903 ◦ 1/3 father of Modern Physical Chemistry ◦ Learn to read by age 3 ◦ 5 th grader at age 8 ◦ His Doctorate Dissertation was not viewed favorably and was originally awarded a 4 th class degree (2.00-2.49 GPA) which was then upgraded to 3 rd class (2.50-2.99GPA)  Doctoral Work led to his NP

11. Svante Arrhenius He proposed 56 different Theses in his dissertation… of which over 23 of them still hold true. ◦ Dissociation of Salts in water  Conductivity ◦ Provided definitions for Acids & Bases ◦ Introduces the notion of Activation Energy ◦ Instrumental in setting up the Nobel Institute & Nobel Prizes  Member of the committee.

12. David Chapman & Max Bodenstein Chapman ◦ Proposes the Steady State hypothesis as part of his studies in photochemical reactions of H 2 and Cl 2 Bodenstein ◦ Similar work done using I 2 ◦ Introduced the notion of chain-reactions ◦ Proposed the enzyme-kinetic rate law

13. Max Trautz & William Lewis Trautz (German) ◦ Linked Max Planck’s work with Arrhenius work… linking effects of light on kinetics ◦ Introduces Collisional Theory in 1916 Lewis (Irish/Welsh/British) ◦ Proposes his theory of chemical reactions (later Collisional Theory) in 1918 ◦ When Molecules collide only a fraction of the collisions lead to a chemical reaction  Connects the work of Arrhenius and van’t Hoff

14. Irving Langmuir and Cyril Hinshelwood Langmuir ◦ Introduced the concept of the “monolayer” ◦ Perform experiments on the rate of reactions at physical interphases (gas-liquid)  It is considered the Father of Surface Chemistry  NP Chemistry in 1932 Hinshelwood ◦ Along with Langmuir proposed that the adsorption of reactants on the surface is the limiting step in heterogeneous catalysis

15. Henry Eyring Theoretical chemist ◦ Develop the Absolute Rate Theory… now known as Transition State Theory ◦ Was never awarded the NP  Arguably the committee did not understand his theory  NP have been awarded to others who use his original work  In 1977 he was awarded the Berzelius Medal by the committee arguably as compensation for the oversight.