Chapter 5: Chemical Kinetics Flashcards
What determines reaction spontaneity
Gibbs Free Energy
what are intermediates
molecules that exist within the course of a reaction but are neither reactants nor products
what is the rate determining step
slowest step that limits maximum rate at which the reaction proceeds
what is collision theory
states that a reaction rate is proportional to the number of effective collisions between reacting molecules
what is required for an effective collision
molecules must be in proper orientation and have sufficient kinetic energy
what is transition state theory
states that molecules form a transition state during a reaction in which the old bonds are partially dissociated and new bonds partially formed
what is the highest point of gibbs free energy in transition state theory
the transition state
what affects reaction rate
1) Concentration
2) Temperature
3) changing the medium
4) Adding a catalyst
what is a homogenous catalyst
catalyst in the same phase as reactants
what is a heterogeneous catalyst
catalyst in a different phase as reactants
how is reaction rate measured
in terms of the rate of disappearance of a reactant or appearance of a product
what is the rate law equation
rate = k [A]^x [B]^y
how is rate law determined
through experimental data
what is the rate order of a reaction
sum of all individual rate orders in rate law
what is a Zero Order Reaction
constant rate that does not depend on the concentration of reactant
how do you affect a zero order reaction
temperature or catalyst
what does a zero order reaction look like on a plot
straight line; slope = -k
What is a first order reaction
non-constant rate that depends on the concentration of reactant
what does a first order reaction look like on a plot
nonlinear; slope of ln[A] vs time = -k
what does a second order reaction look like on a concentration vs time plot
non linear
what is the slope of a second order reaction on a 1/[A] vs time
k
what are broken order reactions
non integer orders
what are mixed order reactions
rate order changes over time
