Chemistry Chapter 5: Chemical Kinetics Flashcards
The change in Gibbs free energy (ΔG) determines whether or not a reaction is _________
spontaneous.
_________ propose a series of steps that make up the overall reaction.
Chemical mechanisms
________ are molecules that exist within the course of a reaction, but are neither reactants nor products overall
Intermediates
The slowest step, also known as the______, limits the maximum rate at which the reaction can proceed
rate-determining step,
The ___________ states that a reaction rate is proportional to the number of effective collisions between the reacting molecules
collision theory
For a collision to be effective, molecules must be in the proper orientation and have sufficient kinetic energy to exceed the ________
activation energy.
The _______ equation is a mathematical way of representing collision theory.
Arrhenius
The _______ theory states that molecules form a transition state or activated complex during a reaction in which the old bonds are partially dissociated and the new bonds are partially formed
transition state
The transition state is the ______ point on a free energy reaction diagram
highest
______ the concentration of reactant will increase reaction rate (except for zero-order reactions) because there are more effective collisions per time
Increasing
Increasing the temperature will increase reaction rate because the particles’ kinetic energy is ______
increased
Adding a catalyst increases reaction rate because it ______the activation energy. Homogeneous catalysts are the same phase as the reactants; heterogeneous catalysts are a different phase
lowers
Reaction rates are measured in terms of the rate of disappearance of a reactant or ______ of a product.
appearance
Rate laws take the form of rate =
rate = k[A]x[B]y
The rate order of a reaction is the ____ of all individual rate orders in the rate law.
sum
______ reactions have a constant rate that does not depend on the concentration of reactant
Zero-order reactions
The rate of a zero-order reaction can only be affected by changing the ______ or adding a catalyst
Temperature
A concentration vs. time curve of a zero-order reaction is a straight line; the slope of such a line is equal to –k.
First-order reactions have a nonconstant rate that depends on the concentration of reactant.
A concentration vs. time curve of a first-order reaction is ______
The slope of a ln [A] vs. time plot is –k for a first-order reaction.
nonlinear
Second-order reactions have a nonconstant rate that depends on the concentration of ______
A concentration vs. time curve of a second-order reaction is nonlinear.
The slope of a [A] vs. time plot is k for a second-order reaction
reactant.
_______ reactions are those with noninteger orders
Broken-order
______ reactions are those that have a rate order that changes over time.
Mixed-order
\+ΔG = endergonic = energy \_\_\_\_\_\_ –ΔG = \_\_\_\_\_\_\_ = energy given off
\+ΔG = endergonic = energy absorbed –ΔG = exergonic = energy given off
