CHM 2046C Sample Module Nine Exam Name:_______________

Module Nine: Chemical Kinetics - Chapter 15	Possible	Actual
A. Rate Law applied to Collision Model (lecture)	10
B. Factors forming the rate Constant-Section 15.5	10
C: Free Radical Mechanism of Halogenation of Alkane (lecture)	10
D. Determination of Rate Orders from Lab Data Section 15.3 p706-712	10
E. 1st, 2nd, zero order Graphical Methods Determination Section 15.4 p716-722.	10
F. Conct-Time Relationships Half Life 1st Order Section 15.4 p712-716	5
G. Mechanism of Reactions Section 15.6 p732-741	20
H. Discussion Question-Chapter 15 study guide & Lecture	10	answer
K. Key Terms - Chapter 15	10
M. Multiple Choice - Chapter 15	15
Module Nine Total:	110

Part A: Law of Mass Action 10 points

In the reaction: A + B ------> C + D ; assuming the reaction is first order with respect to both the reactants A and B;

the rate expression is: Rate = k’[A][B].

(The reverse reaction is not a factor in the initial concentration changes).

Demonstrate the Law of Mass Action in explaining why you multiple the concentration of A times the concentration of B in the rate expression: ( [A][B] ) .

First lets look at a molecule reaction Model: Suppose I had two A molecules and two be molecules in a container, what are the possible collision pathways?

Collision Model: Data Summary:

Now fill in the Mathematical Signs in the table of data:

What does this product represent?

This product represents the total unique reaction pathways possible when you mix two molecules in a container. It is the theoretical number of different collisions which could take place in a container.

Is this product a number greater or less than one?

Obviously, this number is greater than one. The concentrations are measured in moles per liter and a mole is 6.023 x 10²³ molecules which is a very large number.