Answer Happy

1. (32 points) Circle the letter on the right which corresponds to the answer to each question. There is only one correct answer for each question. (i) Which of the following dienes undergoes the least exothermic hydrogenation upon treatment with H2/Pt? A. (E,E) CH3CH=CHCH=CHCH3 B. (E) CH2=CHCH=CHCH2CH3 C. (Z) CH2CH=CHCH2CH=CH2 D. CH2=CHCH2CH2CH=CH2 (ii) Which of the following carbocations is most stable (remember to take resonance structures into account)? + + # + E F G H (iii) How many electrons does the allyl cation have in p-orbitals? I. 2 J. 3 K. 4 L. 5 (iv) Which of the following ions is aromatic? 0 M N O P (v) Which type of reactive intermediate is involved in the treatment of toluene, Ph-CH3, with N- bromosuccinimide? Q. cation R. anion S. radical T. dienophile (vi) Which of the following undergoes the most rapid bromination with N-bromosuccinimide? U. pentane V. 1-pentene W. 2-pentene X. 1,4-pentadiene (vii) Which of the following molecules is not aromatic? Y. Z. AA. BB. (viii) Which of the following is the thermodynamic product obtained upon treatment of 1,3-butadiene with Brz? CC. BrCH2CHBCH=CH2 DD. (E) BrCH2CH=CHCH2Br EE. (Z) BrCH2CH=CHCH Br FF. (E) BrCH2CH=CBCH3