Kinetics test                             75 points                                              chemistry

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

1. In regards to the reaction:  C2H6  +  O2  →  CO2  +  H2O, fill-in the below table using either integers or simplest (improper) fraction. [20 points]

Rate (mM/s)

blah 2  (mM/s)

blah 4  (mM/s)

blah 6  (mM/s)

blah 8  (mM/s)

a.

b.

c.

20.0

d.

 

2. The reaction,  CH3Br  +  OH-  →  CH3OH  +  Br- , the rate law is first-order with respect to OH- and first-order with respect to CH3Br.  When [CH3Br] = 0.010 M and [OH-] = 0.1 M,  the rate is 0.28 M / s  [10 points; based on HW 14.17]

a. What is the value and units of the rate constant ?

b. What is the rate by tripling the concentration of hydroxide ?

3. Based on the following hypothetical data and using graphical analysis (i.e. use the below graph paper & label the axis), determine the order of the reaction:  A  →  B; justify your answer / show your work in regards to any calculations.  [15 points; based on HW 14.33]

Time (minutes)

[A]  (M)

0

200

20

134

40

90

60

60

80

40

100

27

 

blah 10

 

4. Determine the rate law (i.e. value (& units) of the rate constant and the exponents) for the reaction, NO  +  O2  → NO2 based on the following data.   [20 points; based on HW 14.21]

experiment

[NO] (M)

[O2] (M)

Rate (M / s)

1

0.0126

0.0125

1.41 * 10 -2

2

0.0252

0.0250

1.13 * 10 -1

3

0.0252

0.0125

5.64 * 10 -2

5. The activation of the forward reaction and the change in enthalpy is 100 kJ/mol and -23 kJ/mol, respectively.  [10 points; based on HW 14.39]

a. Sketch / label (i.e. both axis, Ea,f, Ea,b, & ΔH) the reaction energy profile

b. What is the activation energy of the backward reaction ?