Name:  _____________________                              date:  __________________               period: _______

kinetics                                    test                  65 points                                                                      chemistry

In problems involving any calculation, show your work in an organized manner, include (i) any relevant equation (or formula), (ii) conversion factor(s), (iii) put the proper units in your calculations and answer, and (iv) have the proper number of significant figures in your answer.

1. Fill-in the below table in regards to the reaction:  C4H10  +  O2  -->  CO2  +  H2O  [10 points]

Rate (mM / sec)

Δ [O2]/Δt  (mM / sec)

Δ [CO2]/Δt  (mM / sec)

8.0

 

 

 

 

32.0


2. Describe the graphical analysis and its basis to estimate the activation energy of a reaction.  Hint:  don’t use the reaction energy profile.  [10 points]

3. Short-answer questions.  [10 points]

a. What is the effect and the basis of the effect of a catalyst ?

b. In regards to the reaction:  A  à  B, what is the order of the reaction based on the below graph; justify / rationalize your answer.

4. In the reaction:  Na2S2O3 (aq) + HCl (aq) --> S (s) + SO2 (g) + H2O (l) + NaCl (aq), the following hypothetical data was obtained; determine the rate law; includes value / units of the rate constant.  [20 points]

Expt

[HCl]; mM

[Na2S2O3]; mM

rate (μM / sec)

1

0.20

0.20

35.0

2

0.80

0.20

70.0

3

0.20

0.40

70.0

5. In regards to a reaction:  A  -->  B, assuming it’s a ___ order reaction, sketch / label a graph of [A] versus time and illustrate the relative (i.e. same, smaller, or larger) half-life for going from 100 to 50 mM versus 50 to 25 mM.    [15 points]

a. Zero

b. First

c. second