To track concentration vs. time, the _________ _________ _________ is determined by a spectrometer when the two reactants mix in a chamber
volumetric flow rate
The instantaneous reaction rate at any time can be found by computing the ________ of the ________ ________.
slope of the tangent line
To avoid complications, we study the rate of reaction under conditions where the ________ __________ makes only a negligible contribution.
Rate=k[A]^n is called a _______ ________ in which k is the __________ constant and n is the ______ of the reactant, both which are determined by __________.
rate law; rate; order; experiment
Differential rate law (or just rate law) expresses how the ______ depends on __________.
We can work backwards from the ______ _______ to find the steps by which the reaction occurs.
Zero-order reactions are most often encountered when a substance such as a __________ ___________ or an ____________ is required for the reaction to occur.
metal surface; enzyme
In a pseudo-first order rate law, the concentration of one reactant is _______ compared with the concentrations of all the others.
a species that is neither a reactant nor a product but that is formed during the reaction sequence
What is the steady-state approximation?
The assumption that the concentration of any intermediate remains constant as the reaction proceeds
To use steady-state approximation, first write the proposed _____________, construct a steady-state expression for each ______________ in which the sum of the rate laws that produce I are then set equal to the sum of the rate laws that consume I, solve for [I1], [I2],....construct an overall _______ ________ for the reaction, and substitute the concentrations of the intermediates to obtain an overall rate law that contains only reactant and/or __________ concentrations.
mechanism; intermediate; rate law; product
Only a small fraction of __________ produces a reaction because not all reach the threshold energy.
Activated complex/transition state
The arrangement of atoms found at the top of the potential energy "hill"
Only collisions with energy greater than the ________ ___________ are able to react.
In order for a collision to lead to a reaction, the collision must involve enough _________ to produce the reaction and the relative ___________ of the reactants must allow formation of any new bonds necessary to produce products.
most rate constants obey the ___________ ___________ to a good approximation, indicating that the collision model is physically reasonable.
What do enzymes do?
They increase the rates of reactions even though the body temperature remains constant.
A catalyst allows the reaction to occur along a pathway with a lower _________ ___________, making a much larger fraction of collisions effective at a given temperature.
A homogenous catalyst is one that is present in the ____ ________ as the reacting molecules.
A heterogeneous catalyst is one that exists in a _______ ________ than that of the reacting molecule, usually as a solid.
__________ refers to the collection of one substance on the surface of another substance.
Heterogeneous catalysis involves four steps:
1) Adsorption and activation of the reactants 2) Migration of the adsorbed reactants on the surface 3) Reaction among the adsorbed substances 4) Escape, or desorption, of the products.
The most effective catalytic materials are transition _______ ________ and ________ metals such as palladium and platinum.
metal oxides; noble
NO forms ozone in the ________ atmosphere, which is harmful, and destroys ozone in the ________ atmosphere.
If A+B--> products, and [A]>>B, then [A] remains about _______. [B] will then exhibit "_______-_____ ______" kinetics and ln[B] vs t will be linear.
constant; pseudo-first order
OH+CH4 --> CH3 + H2O, -d[OH]/dt=
k[OH][CH4], must make [CH4]>>[OH] in order to make [OH] "pseudo-first order