# Transcribed Image Text: Review I Constants Periodic Table For a reaction to occur, bonds must be broken and/or made. This process includes a high-energy transition

Transcribed Image Text: Review I Constants Periodic Table
For a reaction to occur, bonds must be broken and/or made. This process includes a high-energy transition state. Formation of this transition state is energetically unfavorable. The
difference in energy between the reactants and the transition state is called the activation energy. Catalysts can accelerate the chemical reaction by providing a lower energy pathway
between the reactants and the products. This usually involves the formation of a transition state or an intermediate that cannot be formed without the catalyst. The catalyzed reaction
pathway generally has a much lower activation energy barrier than is required for the direct reaction of reactants to products. Notice what catalysts do not do: They do not change the
energy of the reactants, products, or overall reaction. What changes is the activation energy.
No catalyst
With catalyst
Na cataivst
Eac
+ catalvst
Reactants
Energy
Products
Progress of reaction >
The collision theory of reactions states that, for a reaction to occur, molecules must collide with sufficient energy and the proper orientation. A catalyst can increase the rate of reaction by
increasing the probability of the molecules colliding with the correct orientation. Increasing the temperature can also increase the rate of a reaction, as it increases both the energy of the
molecules and the number of collisions between molecules.
The connection among the rate of the reaction, temperature, and activation energy is given by the Arrhenius equation: k = Ae Ba/RI where k is the rate constant for the reaction rate,
Ea is the activation energy, R is the gas constant, equal to 8.314 J/(mol K), T is the temperature in kelvins, and A is the pre-exponential constant for the reaction. The pre-
exponential constant has the same units as k.
Part A
By what factor does increasing the temperature of a reaction from T = 273 K to T, = 283 K increase the rate of reaction? Assume the activation energy (E) of this reaction is
164,500 J and that the pre-exponential constant (A) is 2.1 x 10° s-1.