49. Which of the following compounds is the most reactive toward electrophilic aromatic substitution?

45. Which of the labeled H atoms (1-5) in the following molecule would be predicted to be the most acidic?  (A) 1 (B) 2 (C) 3 (D) 4 (E) 5

46. What is the major product of the following reaction? 

47. Which of the following compounds exhibits the pattern of m/z values shown below? 41, 43, 57, 87, 101, 116 (A) n-propylbromide (B) isopropyl bromide (C) 2-hexanol (D) 2-butanone (E) sec-butyl isopropyl ether

48. Which of the following statements correctly pertains to a pair of enantiomers? (A) They rotate the plane of polarized light by exactly the same amounts and in opposite directions. (B) They rotate the plane of polarized light by differing amounts and in opposite directions. (C) They rotate the plane of polarized light by differing amounts and in the same directions. (D) They have the same specific rotation, but they have different melting points. (E) They have the same melting points, but they have different boiling points.

50. What is the product of the following reaction? 

51. What is the major product of the following reaction? 

52. Which of the following compounds has the most signals in the noise-decoupled 13C NMR spectrum? (A) o-dibromobenzene (B) m-dibromobenzene (C) p-dibromobenzene (D) 1,3,5-tribromobenzene (E) 1,2,3,4-tetrabromobenzene

53. Identify the aromatic compounds.  (A) I and II (B) II and III (C) I and III (D) III and IV (E) I, III and IV

54. Which of the following compounds has the highest melting point? (A) benzene (B) toluene (C) o-dichlorobenzene (D) m-dichlorobenzene (E) p-dichlorobenzene

55. Provide the structure of the major organic product in the following reaction. (A)(B)(C)(D)(E) none of these