Journal Entry:

The conversion of ozone into molecular oxygen occurs in the stratosphere according to the following equation.

2O_{3 (g)} --> 3O_{2 (g)} Rate=k[O₃ ]²[O₂]^-1

Which of the following statements is true regarding the rate of the breakdown of ozone (O₃) into molecular oxygen (O₂) as stated by the rate law?
(A) The catalyst that converts ozone to oxygen is inhibited by oxygen.
(B) The rate at which ozone is converted to oxygen gas increases as the concentration of oxygen decreases.
(C) There is an inverse square relationship between ozone and oxygen concentrations.
(D) The conversion of oxygen to ozone is faster than the conversion of ozone to oxygen.

Learning Intentions

• We will learn how to analyze concentration vs time data to determine the rate law for zeroth, first and second order reaction. 

• We will learn how to calculate rate constant and its unit.

• We will learn how and what changes rate constant for a reaction

Closing Task:

You can write a rate law equation for a set of data and determine the appropriate unit for the rate constant.

Content Standards being covered:

Catalysts function by lowering the activation energy of an elementary step in a reaction mechanism, and by providing a new and faster reaction mechanism. (E.K. 4.D.1)

The rate law shows how the rate depends on reactants concentrations. (E.K. 4.A.2)