2.  Rate laws can be converted into equations that tell us what the concentration of the reactants or products are at any time  Calculus required to derive the equations but not to use them

3.  Rate = k  With calculus it can be changed to an equation that relates the starting conc ([A] o ) to the conc at any other time (t)  [A] = -kt + [A] o

4.  Plot of [A] vs t is linear with a slope equal to k

5.  Find the conc of a reactant at some time after the reaction started  Find the time required for a given fraction of a sample to react  Find the time required for a reactant to reach a certain concentration

6.  Rate = k[A]  ln[A] = - kt + ln[A] o

7.  Plot of ln[A] vs t is linear

8.  The first order constant for the hydrolysis of a certain insecticide in water at 12°C is 1.45/yr. A quantity of this insecticide is washed into a lake in June, leading to an overall concentration of 5 x 10 -7 g/cm 3 of water. Assume that the effective temp of the lake is also 12°C. A) what is the conc of the insecticide in June of the following year? B) How long will it take for the conc of the insecticide to drop to 3.0 x 10 -7 g/cm 3 ?

9.  The decomposition of dinitrogen pentoxide is studied over time and the results are given in in the table on pg.573. a) Verify if this is a first order reaction. b) Calculate the value of the rate constant c) Find the concentration after 150 sec.

10.  Time required for the concentration of a reactant to decrease to halfway between its initial and final values  Time when [A]= ½ [A] o  t 1/2 =.693/k

11.  What is the half life of the insecticide in the lake from the previous example?

12.  Rate = k[A] 2  1/[A] = kt + 1/[A] o  Plot of 1/[A] vs t is linear

14.  The following data was obtained for the decomposition of nitrogen dioxide. Is the reaction first or second order? What is the rate constant? Time (s) [NO 2 ] 0.0100 50.0079 100.0065 200.0048 300.0038