09 - bonds will begin to form and the reactants are on...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
12/3/09 Chapter 15 - Molecularity number of molecules colliding together for a reaction - If the concentration of a reagent was so great that its concentration did not change over the course of a reaction, then the reaction was zero order in that reagent For a reaction to procedd the collision must be: 1)Sufficianelty energetic 2) Properly oriented Arrhenius equation tells us the fraction of collisiosn with sufficient energy to produce a rxn Fraction of collisions with sufficient energy for reaction is given by: f=e -Ea/RT Pre-exponential term, tells us what fraction of collisions w/ sufficient energy to produce a reaction will actually produce reaction A is transmission/frequency factor: A=pz Think of transition state theory At a head on collision, KE is converted to PE -If energy is less than E a , molecules collide with no rxn -If energy is sufficient & molecules are properly oriented, a reaction occurs -If KE is sufficient to overcome steric repulsions, rearrange nuclei, break bonds, new
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: bonds will begin to form, and the reactants are on their way to being a product-At some point, we reach a high energy species that is neither reactant nor product call this species a transition state or activated complex-E a is the arrhenius equation is equal to ∆G x (Double dagger)-Species at maximum of our rxn, coordinate plot is referred to as transition state (TS)-Mechanisms are described by several individual or microscopic steps that contribute sequentially-A mechanism – a series of elementary steps – must meet three criteria 1) Elementary steps must add up to balanced equation 2) Elementary steps must by physically reasonable 3) Elementary must correlate with rate law Catalysis-A catalyst is a species that speeds the attainment of equilibrium without being formed or consumed in the process-Cataysts lower activation energyx...
View Full Document

This note was uploaded on 09/19/2011 for the course CHEM 43L taught by Professor Therien during the Fall '09 term at Duke.

Ask a homework question - tutors are online