Ch. 21 & 14 nuclear chemistry & kinetics test         80 points          AP Chemistry

 

Show your work in an organized manner, include any relevant formula / conversion factors, have the proper units in your work, and proper number of significant figures in your answer.

 

1. A hypothetical (?) radioactive isotope with a half-life of 15 years, originally had 225 mCi of the isotope, but currently has 9875 µ Ci. What is the elapsed time ? [10 points]

 

2. pick one problem; clearly identify your choice; if you do both questions, your score = lowest score. [5 points]

a. What does the equation: E = mc2 mean (in the context of a nuclear reaction) ?

b. Describe the basis of the atomic bomb ?


3. Write the nuclear equation for the following (hypothetical ?) nuclear reaction: [10 points]

a. the fusion reaction involving 12C and 7Li

b. the alpha decay of 226Ra

c. the β¯ decay of 32Si

 

4. In the combustion of butane, the rate of consumption of oxygen is 5.0 mM / sec. What is the rate of ___. [10 points]

a. consumption of butane

b. production of water

 

5. Determine the rate law, include the value of the rate constant, in the combustion of ethane, based on the following hypothetical (?) experimental data. [10 points]

Expt

Initial rate (mM / sec)

[ethane] (M)

[oxygen] (M)

1

5.0

1.0

2.0

2

10.0

1.0

4.0

3

135

3.0

6.0

 

6. Based on the following hypothetical (?) reaction mechanism [15 points]

a. what is the chemical reaction described by this mechanism ?

b. identify / label all reaction intermediate(s) and catalyst(s)

c. what is the rate law ?

 

7. A chemical reaction generates 25 kJ / mole, where the activation energy of the forward reaction is 75 kJ / mole. What is the activation energy of the reverse reaction ? Justify your answer by sketching / labeling the reaction energy profile for this reaction. [10 points]

 

8. old topic [10 points]

Sketch the structural formula of propyl alcohol and two of its isomers (i.e. 3 isomers).