89.1 Introduction of Chemical Kinetics Levine p. 528-529 17.1 reaction kinetics rate of reaction rate laws reaction mechanism
§9.1 Introduction of Chemical Kinetics Levine p. 528-529 17.1 reaction kinetics rate of reaction, rate laws, reaction mechanism
89.1 Introduction of Chemical Kinetics (1)What is chemical kinetics? (1)What do we concern about a chemical reaction? N,+3H,C1040m 22NH3 1)Stoichiometric: Reactants, products and their ratios, balance of the equation 2)Thermodynamic: Direction; equilibrium; yields. 3)Kinetic: Rate and mechanism rate; catalyst; mechanism; selectivity
(1) What is chemical kinetics？ 1) Stoichiometric: Reactants, products and their ratios, balance of the equation. 3) Kinetic: Rate and mechanism. rate; catalyst; mechanism; selectivity. 2) Thermodynamic: Direction; equilibrium; yields. (1) What do we concern about a chemical reaction? §9.1 Introduction of Chemical Kinetics
89.1 Introduction of Chemical Kinetics (1)What is chemical kinetics? (2)Definition: a branch of chemistry that concerns reaction rate and reaction mechanism. (3) Brief advancements of chemical kinetics (1)1850s-1910s: Empirical kinetics (2)1910s-1950s: Elementary reactions (3)1950s-present: Microscopic kinetics: molecular dynamics, state-to state dynamics
(3) Brief advancements of chemical kinetics (1) 1850s-1910s: Empirical kinetics (2) 1910s-1950s: Elementary reactions; (3) 1950s-present: Microscopic kinetics: molecular dynamics, state-tostate dynamics (2) Definition: A branch of chemistry that concerns reaction rate and reaction mechanism. (1) What is chemical kinetics？ §9.1 Introduction of Chemical Kinetics
89.1 Introduction of Chemical Kinetics (1)What is chemical kinetics? (4)Main concerns of chemical kinetics 1)Reaction rate: influential factors of reaction rate, such as concentration, temperature catalysts etc. --rate law 2)Reaction mechanism: the series of steps by which a reaction takes place. 3)structure-dependence of reactivity: the correlation between molecular structure and reaction potentiality(structural chemistry)
(4) Main concerns of chemical kinetics: 1) Reaction rate: influential factors of reaction rate, such as concentration, temperature, catalysts, etc. -- rate law. 2) Reaction mechanism: the series of steps by which a reaction takes place. 3) structure-dependence of reactivity: the correlation between molecular structure and reaction potentiality (structural chemistry). (1) What is chemical kinetics？ §9.1 Introduction of Chemical Kinetics
89.1 Introduction of Chemical Kinetics (2)Elementary reaction H2+ Br2=2HBr H+=2HI 1)Br2+M=2Br·+M 1)L2+M=2I+M 2)Br·+H2=HBr+H 2)2I+H2=2H 3)H+ Br2=HBr+ Br. 4)H+ HBr=H,+ Br. multistep reaction 5)2Br+M=Br2+ M Elementary reaction: the reaction that completes in one act Intermediate: the species formed in one step and consumed in a subsequent step and never seen as a product
H2 + I2 = 2HI 1) I2 +M = 2I + M 2) 2I + H2 = 2HI H2 + Br2 = 2HBr 1) Br2 + M = 2Br + M 2) Br + H2 = HBr + H 3) H + Br2 = HBr + Br 4) H + HBr = H2 + Br 5) 2Br + M = Br2 + M multistep reaction Elementary reaction: the reaction that completes in one act Intermediate: the species formed in one step and consumed in a subsequent step and never seen as a product (2) Elementary reaction §9.1 Introduction of Chemical Kinetics