8. Consider the spectrum illustrated below. Which of the following structures will be best for this spectrum? 
(A)
(B)
(C)
(D)
(E) None of the above

4. What will be the major product of the following reaction?(A)(B)(C)(D) (E) None of the above 

5. Which of the following reactions would not show primary kinetic isotope effect? (A)(B)(C)(D)(E) None of the above 

6. When bromide AK is treated with NaOEt， four2- butene are possible products. (A) AK-a and AK-b are obtained (B) AK-a and AK-d are obtained(C) AK-b and AK-c are obtained (D) None of the above

7. Solvent is an important factor in the nucleophilic reaction. We classified solvent into several categories. What is the best description of acetone? Acetone is: (A) nonpolar aprotio (B) polar aprotic (C) polar protic (D) nonpolar protic (E) None of the above

9. The average mass of a boron atom is 10.81. If you were able to isolate a single boron atom, what is the chance that you would randomly get an atom with mass 10.81?  (A) 0% (B) 0.81% (C) about 11% (D) 10.81% (E) greater than 50%.

10. Which of the statements below correctly describes the chair conformations of trans-1,4-dimethylcyclohexane? | (A) The two chair conformations are of equal energy. | (B) The higher energy chair conformation contains one axial methyl group and one equatorial methyl group. | (C) The lower energy chair conformation contains one axial methyl group and one equatorial methyl group. | (D) The higher energy chair conformation contains two axial methyl groups. | (E) The lower energy chair conformation contains two axial methyl groups. |

11. Which is a measure of the randomness of a system?(A) entropy (B) enthalpy (C) free energy (D) halogenation (E) stoichiometry 

12. Which of the following species is the least nucleophilic? (A) H20 (B) BF3 (C) (CH3)3N (D) CH3O- (E) CH- 

13. HBr can be added to an alkene in the presence of peroxides (ROOR). What function does the peroxide serve in this | reaction? (A) nucleophile (B) electrophile (C) radical chain initiator j (D) acid catalyst . (E) solvent |

14. Which of the following terms best describes the reactive nature of a Grignard reagent? (A) carbocation (B) free radical (C) electrophile (D) nucleophile (E) carbene